Added int nanometer example in README

README.md

@@ -1,306 +1,233 @@
-# zig_units
+# dimal — Dimensional Analysis for Zig
 
-**Compile-time dimensional analysis for Zig.**
+A comptime-first dimensional analysis module for Zig. If you try to add meters to seconds, **it won't compile**. That's the point.
 
-`zig_units` lets you attach physical units to numeric values so that
+Born from a space simulation where `i128` positions were needed to avoid float imprecision far from the origin, this module grew into a full physical-unit type system with zero runtime overhead.
-dimension mismatches become *compile errors* rather than silent bugs.
-At runtime a `Quantity` is nothing but a single number — zero overhead.
 
-```
+> **Source:** [git.bouvais.lu/adrien/zig-dimal](https://git.bouvais.lu/adrien/zig-dimal)  
-velocity = distance / time   →  L¹T⁻¹  ✓
+> **Minimum Zig version:** `0.16.0`
-force    = mass + velocity   →  compile error: M¹ ≠ L¹T⁻¹
-```
-
-Requires **Zig 0.16** or later.
 
 ---
 
 ## Features
 
-- Seven SI base dimensions (`L M T I Tp N J`)
+- **100% comptime** — all dimension and unit tracking happens at compile time. No added memory, *almost* native performance.
-- Full SI prefix support (`P T G M k h da d c m u n p f`)
+- **Compile-time dimension errors** — adding `Meter` to `Second` is a compile error, not a runtime panic.
-- Custom time aliases (`.min`, `.hour`, `.year`)
+- **Automatic unit conversion** — use `.to()` to convert between compatible units (e.g. `km/h` → `m/s`). Scale factors are resolved at comptime.
-- Automatic scale conversion on add/sub (finer unit wins)
+- **Full SI prefix support** — `pico`, `nano`, `micro`, `milli`, `centi`, `deci`, `kilo`, `mega`, `giga`, `tera`, `peta`, and more.
-- `Quantity(T, dims, scales)` — scalar, any numeric backing type
+- **Time scale support** — `min`, `hour`, `year` built in.
-- `QuantityVec3` — three-component vector with the same guarantees
+- **Scalar and Vector types** — operate on individual values or fixed-size arrays with the same dimensional safety.
-- Unicode superscript formatting (`9.81m.s⁻²`)
+- **Built-in physical quantities** — `dma.Base` provides ready-made types for `Velocity`, `Acceleration`, `Force`, `Energy`, `Pressure`, `ElectricCharge`, `ThermalConductivity`, and many more.
-- Integer-safe square root for `Vec3.length()`
+- **Rich formatting** — values print with their unit automatically: `9.81m.s⁻²`, `42m.kg.s⁻¹`, `0.172km`.
-- All dimension tracking happens at `comptime` — no runtime cost
+- **`i128` support** — the whole reason this exists. Use large integers for high-precision fixed-point positions without manual conversion.
+- **Tests and benchmarks included** — run them and see how it performs on your machine (results welcome!).
+
+---
+
+## The 7 SI Base Dimensions
+
+| Symbol | Dimension            | SI Unit  |
+|--------|----------------------|----------|
+| `L`    | Length               | `m`      |
+| `M`    | Mass                 | `g`      |
+| `T`    | Time                 | `s`      |
+| `I`    | Electric Current     | `A`      |
+| `Tp`   | Temperature          | `K`      |
+| `N`    | Amount of Substance  | `mol`    |
+| `J`    | Luminous Intensity   | `cd`     |
 
 ---
 
 ## Installation
 
-### Add as a Zig dependency
+### 1. Fetch the dependency
 
-```bash
+```sh
-zig fetch --save https://github.com/YOUR_USERNAME/zig_units/archive/refs/heads/main.tar.gz
+zig fetch --save git+https://git.bouvais.lu/adrien/zig-dimal#b9647e04266e3f395cfd26b41622b0c119a1e5be
 ```
 
-This adds an entry to your `build.zig.zon`.  Then wire it up in your
+This will add the following to your `build.zig.zon` automatically:
-`build.zig`:
 
 ```zig
-const zig_units = b.dependency("zig_units", .{
-    .target  = target,
-    .optimize = optimize,
-});
-my_module.addImport("zig_units", zig_units.module("zig_units"));
-```
-
-### Local path (monorepo / development)
-
-```zig
-// build.zig.zon
 .dependencies = .{
-    .zig_units = .{ .path = "../zig_units" },
+    .dimal = .{
+        .url = "git+https://git.bouvais.lu/adrien/zig-dimal#b9647e04266e3f395cfd26b41622b0c119a1e5be",
+        .hash = "dimal-0.1.0-WNhSHvomAQAX1ISvq9ZBal-Gam6078y8hE67aC82l63V",
+    },
 },
 ```
 
----
+### 2. Wire it up in `build.zig`
-
-## Quick start
 
 ```zig
-const units     = @import("zig_units");
+const std = @import("std");
-const Quantity  = units.Quantity;
-const Dims      = units.Dimensions;
-const Scales    = units.Scales;
 
-// Define named unit types
+pub fn build(b: *std.Build) void {
-const Meter    = Quantity(f32, Dims.init(.{ .L = 1 }),           Scales.init(.{}));
+    const target = b.standardTargetOptions(.{});
-const KiloMeter= Quantity(f32, Dims.init(.{ .L = 1 }),           Scales.init(.{ .L = .k }));
+    const dimal = b.dependency("dimal", .{}).module("dimal");
-const Second   = Quantity(f32, Dims.init(.{ .T = 1 }),           Scales.init(.{}));
-const MPerSec  = Quantity(f32, Dims.init(.{ .L = 1, .T = -1 }), Scales.init(.{}));
 
-const dist = Meter{ .value = 100.0 };
+    const exe = b.addExecutable(.{
-const t    = Second{ .value = 5.0 };
+        .name = "my_project",
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/main.zig"),
+            .target = target,
+            .imports = &.{.{
+                .name = "dimal",
+                .module = dimal,
+            }},
+        }),
+    });
+    b.installArtifact(exe);
+}
+```
 
-// Dimension is tracked automatically — vel has type L¹T⁻¹
+### 3. Import in your code
-const vel = dist.divBy(t);
 
-// Convert to an explicit type (same dims required, compile error otherwise)
+```zig
-const vel2 = vel.to(MPerSec);
+const dma = @import("dimal");
-
+const Scalar     = dma.Scalar;
-// Cross-scale addition: km + m → result in metres (finer scale)
+const Dimensions = dma.Dimensions;
-const km  = KiloMeter{ .value = 1.0 };
+const Scales     = dma.Scales;
-const sum = km.add(dist);   // 1100 m
 ```
 
 ---
 
-## API reference
+## Quick Start
 
-### `Quantity(T, dims, scales)`
+### Defining unit types
 
-| Member | Kind | Description |
+A `Scalar` type is parameterized by three things: the numeric type (`f64`, `i128`, …), the dimensions (which physical quantities, and their exponents), and the scales (SI prefixes or custom time units).
-|---|---|---|
-| `value` | field | The raw numeric value |
-| `ValueType` | comptime | Alias for `T` |
-| `dims` | comptime | The `Dimensions` of this type |
-| `scales` | comptime | The `Scales` of this type |
-| `Vec3` | comptime | The matching `QuantityVec3` type |
-| `add(rhs)` | fn | Same-dimension addition, finer scale |
-| `sub(rhs)` | fn | Same-dimension subtraction, finer scale |
-| `mulBy(rhs)` | fn | Multiplication, dims are added |
-| `divBy(rhs)` | fn | Division, dims are subtracted |
-| `scale(s: T)` | fn | Dimensionless scalar multiply |
-| `to(Dest)` | fn | Convert to another `Quantity` type (same dims) |
-| `vec3()` | fn | Broadcast scalar to a `Vec3` |
-| `format(writer)` | fn | Print `value + unit string` |
-
-### `QuantityVec3`
-
-Obtained via `SomeQuantity.Vec3`.
-
-| Member | Kind | Description |
-|---|---|---|
-| `x, y, z` | fields | The three components |
-| `zero` | comptime | `(0, 0, 0)` |
-| `one` | comptime | `(1, 1, 1)` |
-| `initDefault(v)` | fn | Broadcast scalar to all components |
-| `add(rhs)` | fn | Component-wise addition |
-| `sub(rhs)` | fn | Component-wise subtraction |
-| `mulBy(rhs)` | fn | Component-wise element-wise multiply |
-| `divBy(rhs)` | fn | Component-wise element-wise divide |
-| `mulByScalar(q)` | fn | Multiply by a scalar `Quantity` |
-| `divByScalar(q)` | fn | Divide by a scalar `Quantity` |
-| `scale(s: T)` | fn | Dimensionless scalar multiply |
-| `negate()` | fn | Negate all components |
-| `to(DestQ)` | fn | Convert to another vector quantity type |
-| `lengthSqr()` | fn | Squared Euclidean length (no sqrt) |
-| `length()` | fn | Euclidean length (integer-safe) |
-| `format(writer)` | fn | Print `(x, y, z) + unit string` |
-
-### `Dimensions`
-
-A comptime struct storing a signed exponent per SI base dimension.
 
 ```zig
-const Dims = @import("zig_units").Dimensions;
+const Meter     = Scalar(f64, .init(.{ .L = 1 }),            .init(.{}));
-
+const NanoMeter = Scalar(i64, .init(.{ .L = 1 }),            .init(.{ .L = .n }));
-// Acceleration: L¹ T⁻²
+const KiloMeter = Scalar(f64, .init(.{ .L = 1 }),            .init(.{ .L = .k }));
-const accel_dims = Dims.init(.{ .L = 1, .T = -2 });
+const Second    = Scalar(f64, .init(.{ .T = 1 }),            .init(.{}));
+const Velocity  = Scalar(f64, .init(.{ .L = 1, .T = -1 }),  .init(.{}));
+const Kmh       = Scalar(f64, .init(.{ .L = 1, .T = -1 }),  .init(.{ .L = .k, .T = .hour }));
 ```
 
-| Function | Description |
+Or use the pre-built helpers from `dma.Base`:
+
+```zig
+const Acceleration = dma.Base.Acceleration.Of(f64);
+const KmhSpeed     = dma.Base.Speed.Scaled(f64, Scales.init(.{ .L = .k, .T = .hour }));
+```
+
+### Kinematics example
+
+```zig
+const v0    = Velocity{ .value = 10.0 };  // 10 m/s
+const accel = Acceleration{ .value = 9.81 }; // 9.81 m/s²
+const time  = Second{ .value = 5.0 };     // 5 s
+
+// d = v₀t + ½at²
+const d1 = v0.mulBy(time);                     // → Meter
+const d2 = accel.mulBy(time.mulBy(time)).scale(0.5); // → Meter
+const dist = d1.add(d2);
+
+const v_final = v0.add(accel.mulBy(time));
+
+std.debug.print("Distance: {d} | {d}\n", .{ dist, dist.to(KiloMeter) });
+// Distance: 172.625m | 0.172625km
+
+std.debug.print("Final speed: {d:.2}\n", .{v_final});
+// Final speed: 59.05m.s⁻¹
+```
+
+### Unit conversion
+
+`.to()` converts between compatible units at comptime. Mixing incompatible dimensions is a **compile error**.
+
+```zig
+const speed_kmh = Kmh{ .value = 120.0 };
+const speed_ms  = speed_kmh.to(Velocity); // 33.333... m/s — comptime ratio
+
+// This would NOT compile:
+// const bad = speed_kmh.to(Second); // "Dimension mismatch in to: L1T-1 vs T1"
+```
+
+### Working with Vectors
+
+Every `Scalar` type exposes a `.Vec3` and a generic `.Vec(n)`:
+
+```zig
+const Vec3Meter = Meter.Vec3; // or: Vector(3, Meter)
+
+const pos = Vec3Meter{ .data = .{ 100, 200, 300 } };
+const t   = Second{ .value = 10 };
+
+const vel = pos.divByScalar(t); // → Vec3 of Velocity (m/s)
+
+std.debug.print("{d}\n", .{vel}); // (10, 20, 30)m.s⁻¹
+```
+
+Vectors support: `add`, `sub`, `mulBy`, `divBy`, `mulByScalar`, `divByScalar`, `negate`, `to`, `length`, `lengthSqr`.
+
+---
+
+## API Reference
+
+### `Scalar(T, dims, scales)`
+
+| Method | Description |
 |---|---|
-| `init(struct_literal)` | Create from named exponents; unset dims default to 0 |
+| `.add(rhs)` | Add two quantities of the same dimension. Auto-converts scales. |
-| `initFill(val: i8)` | Set all exponents to `val` |
+| `.sub(rhs)` | Subtract. Auto-converts scales. |
-| `get(dim)` | Read a single exponent |
+| `.mulBy(rhs)` | Multiply — dimensions are **summed**. `m * s⁻¹` → `m·s⁻¹`. |
-| `set(dim, val)` | Write a single exponent |
+| `.divBy(rhs)` | Divide — dimensions are **subtracted**. `m / s` → `m·s⁻¹`. |
-| `add(a, b)` | Component-wise sum (for `mulBy`) |
+| `.to(DestType)` | Convert to another unit of the same dimension. Compile error on mismatch. |
-| `sub(a, b)` | Component-wise difference (for `divBy`) |
+| `.vec3()` | Wrap the value in a `Vec3` of the same type. |
-| `eql(a, b)` | Equality check |
+| `.Vec(n)` | Get the `Vector(n, Self)` type. |
-| `str()` | Comptime human-readable string, e.g. `"L1T-2"` |
 
-### `Scales`
+### `dma.Base` — Pre-built quantities
 
-A comptime struct storing a `UnitScale` per SI base dimension.
+A selection of what's available (call `.Of(T)` for base units, `.Scaled(T, scales)` for custom scales):
 
-```zig
+`Meter`, `Second`, `Gramm`, `Kelvin`, `ElectricCurrent`, `Speed`, `Acceleration`, `Inertia`, `Force`, `Pressure`, `Energy`, `Power`, `Area`, `Volume`, `Density`, `Frequency`, `Viscosity`, `ElectricCharge`, `ElectricPotential`, `ElectricResistance`, `MagneticFlux`, `ThermalCapacity`, `ThermalConductivity`, and more.
-const Scales = @import("zig_units").Scales;
 
-// Kilometres per nanosecond
+### `Scales` — SI prefixes
-const spd_scales = Scales.init(.{ .L = .k, .T = .n });
-```
 
-| `UnitScale` variant | Factor |
+| Tag | Factor |
 |---|---|
-| `.P` | ×10¹⁵ |
+| `.P` | 10¹⁵ |
-| `.T` | ×10¹² |
+| `.T` | 10¹² |
-| `.G` | ×10⁹ |
+| `.G` | 10⁹ |
-| `.M` | ×10⁶ |
+| `.M` | 10⁶ |
-| `.k` | ×10³ |
+| `.k` | 10³ |
-| `.h` | ×10² |
+| `.none` | 1 |
-| `.da` | ×10¹ |
+| `.c` | 10⁻² |
-| `.none` | ×1 |
+| `.m` | 10⁻³ |
-| `.d` | ×10⁻¹ |
+| `.u` | 10⁻⁶ |
-| `.c` | ×10⁻² |
+| `.n` | 10⁻⁹ |
-| `.m` | ×10⁻³ |
+| `.p` | 10⁻¹² |
-| `.u` | ×10⁻⁶ |
+| `.f` | 10⁻¹⁵ |
-| `.n` | ×10⁻⁹ |
+| `.min` | 60 |
-| `.p` | ×10⁻¹² |
+| `.hour` | 3600 |
-| `.f` | ×10⁻¹⁵ |
+| `.year` | 31 536 000 |
-| `.min` | ×60 (seconds) |
-| `.hour` | ×3 600 |
-| `.year` | ×31 536 000 |
 
 ---
 
-## Examples
+## Running Tests and Benchmarks
 
-### Kinematics
+```sh
-
-```zig
-const Meter  = Quantity(f64, Dims.init(.{ .L = 1 }),           Scales.init(.{}));
-const Second = Quantity(f64, Dims.init(.{ .T = 1 }),           Scales.init(.{}));
-
-const pos  = Meter{ .value = 200.0 };
-const time = Second{ .value = 8.0 };
-
-const vel  = pos.divBy(time);        // L¹T⁻¹  — 25 m/s
-const accel = vel.divBy(time);       // L¹T⁻²  — 3.125 m/s²
-```
-
-### Cross-scale addition
-
-```zig
-const KM = Quantity(i64, Dims.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-const M  = Quantity(i64, Dims.init(.{ .L = 1 }), Scales.init(.{}));
-
-const a = KM{ .value = 2 };   // 2 km
-const b = M{ .value = 500 };  // 500 m
-
-const sum = a.add(b);          // result scale = metres (finer) → 2500 m
-```
-
-### Time conversion
-
-```zig
-const Hour   = Quantity(i64, Dims.init(.{ .T = 1 }), Scales.init(.{ .T = .hour }));
-const Minute = Quantity(i64, Dims.init(.{ .T = 1 }), Scales.init(.{ .T = .min  }));
-const Second = Quantity(i64, Dims.init(.{ .T = 1 }), Scales.init(.{}));
-
-const h   = Hour{ .value = 2 };
-const min = h.to(Minute);     // 120
-const sec = min.to(Second);   // 7200
-```
-
-### Vec3 velocity
-
-```zig
-const Meter  = Quantity(f32, Dims.init(.{ .L = 1 }), Scales.init(.{}));
-const Second = Quantity(f32, Dims.init(.{ .T = 1 }), Scales.init(.{}));
-
-const pos  = Meter.Vec3{ .x = 30.0, .y = 60.0, .z = 90.0 };
-const time = Second{ .value = 3.0 };
-
-const vel  = pos.divByScalar(time);   // Vec3 with dims L¹T⁻¹
-const dist = vel.length();            // Euclidean length
-```
-
-### Dimension mismatch — compile error
-
-```zig
-const Meter  = Quantity(f32, Dims.init(.{ .L = 1 }), Scales.init(.{}));
-const Second = Quantity(f32, Dims.init(.{ .T = 1 }), Scales.init(.{}));
-
-const d = Meter{ .value = 5.0 };
-const t = Second{ .value = 2.0 };
-
-// This will NOT compile:
-const bad = d.add(t);  // error: Dimension mismatch in add: L1 vs T1
-```
-
----
-
-## Running the tests
-
-```bash
 zig build test
+zig build benchmark
 ```
 
-The test suite covers scalar and vector arithmetic, cross-scale operations,
+Benchmark results are very welcome — feel free to share yours!
-conversion chains, negative values, formatting, and an optional benchmark
-(`"Comprehensive Benchmark: All Ops × All Types"`).
 
 ---
 
-## Project layout
+## Roadmap / Known Limitations
 
-```
+- More operations beyond `add`, `sub`, `mulBy`, `divBy` (e.g. `pow`, `sqrt`).
-zig_units/
+- SIMD acceleration for `Vector` operations.
-├── build.zig          # Build script; exposes the "zig_units" module
+- Some paths may still fall back to runtime computation — optimization ongoing.
-├── build.zig.zon      # Package manifest
+- More test coverage.
-├── src/
-│   ├── main.zig       # Quantity, QuantityVec3, tests
-│   ├── Dimensions.zig # SI base dimensions + comptime arithmetic
-│   ├── Scales.zig     # SI prefixes + scale helpers
-│   └── helper.zig     # Internal utilities (isInt, printSuperscript)
-└── README.md
-```
-
----
-
-## Design notes
-
-**Why comptime parameters?**  Zig's `comptime` means the compiler can
-evaluate all dimension arithmetic before any machine code is generated.
-Two quantities with mismatched dimensions simply fail to compile —
-there is no runtime overhead and no need for exception handling.
-
-**Scale selection on arithmetic.**  When two operands have different
-scales (e.g. km and m), `zig_units` automatically picks the finer
-(smaller-factor) scale for the result.  This prevents silent precision
-loss at the cost of an automatic rescaling of both operands.
-
-**Integer backing types.**  Division uses an `f64` intermediate and
-rounds back to the integer type.  For best accuracy, prefer `f32`/`f64`
-for quantities that will be divided frequently.
 
 ---
 
 ## License
 
-MIT — see `LICENSE` for details.
+See the repository for license details.

build.zig

@@ -2,40 +2,38 @@ const std = @import("std");
 
 pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{ .preferred_optimize_mode = .ReleaseSmall });
+    const optimize = b.standardOptimizeOption(.{});
-    const exe = b.addExecutable(.{
+
-        .name = "Zig_Units",
+    // 1. Define the module so other projects can import it
+    _ = b.addModule("dimal", .{
+        .root_source_file = b.path("src/main.zig"),
+    });
+
+    const exe_tests = b.addTest(.{
         .root_module = b.createModule(.{
             .root_source_file = b.path("src/main.zig"),
             .target = target,
             .optimize = optimize,
+        }),
+        .test_runner = .{ .path = b.path("test_runner.zig"), .mode = .simple },
+    });
+
+    const run_exe_tests = b.addRunArtifact(exe_tests);
+    const test_step = b.step("test", "Run tests");
+    test_step.dependOn(&run_exe_tests.step);
+
+    const bench_exe = b.addExecutable(.{
+        .name = "benchmark",
+        .root_module = b.createModule(.{
+            .root_source_file = b.path("src/benchmark.zig"),
+            .target = target,
             .imports = &.{},
         }),
     });
 
-    b.installArtifact(exe);
+    b.installArtifact(bench_exe);
-    const run_step = b.step("run", "Run the app");
 
-    const run_cmd = b.addRunArtifact(exe);
+    const run_bench = b.addRunArtifact(bench_exe);
-    run_step.dependOn(&run_cmd.step);
+    const bench_step = b.step("benchmark", "Run the benchmark suite");
-
+    bench_step.dependOn(&run_bench.step);
-    run_cmd.step.dependOn(b.getInstallStep());
-
-    if (b.args) |args| {
-        run_cmd.addArgs(args);
-    }
-
-    const exe_tests = b.addTest(.{
-        .root_module = exe.root_module,
-        .test_runner = .{
-            .path = .{ .cwd_relative = "test_runner.zig" },
-            .mode = .simple,
-        },
-    });
-
-    // A run step that will run the second test executable.
-    const run_exe_tests = b.addRunArtifact(exe_tests);
-
-    const test_step = b.step("test", "Run tests");
-    test_step.dependOn(&run_exe_tests.step);
 }

build.zig.zon

@@ -1,81 +1,13 @@
 .{
-    // This is the default name used by packages depending on this one. For
+    .name = .dimal,
-    // example, when a user runs `zig fetch --save <url>`, this field is used
+    .version = "0.1.0",
-    // as the key in the `dependencies` table. Although the user can choose a
+    .fingerprint = 0x9453b1ff1e52d858,
-    // different name, most users will stick with this provided value.
-    //
-    // It is redundant to include "zig" in this name because it is already
-    // within the Zig package namespace.
-    .name = .Zig_Units,
-    // This is a [Semantic Version](https://semver.org/).
-    // In a future version of Zig it will be used for package deduplication.
-    .version = "0.0.0",
-    // Together with name, this represents a globally unique package
-    // identifier. This field is generated by the Zig toolchain when the
-    // package is first created, and then *never changes*. This allows
-    // unambiguous detection of one package being an updated version of
-    // another.
-    //
-    // When forking a Zig project, this id should be regenerated (delete the
-    // field and run `zig build`) if the upstream project is still maintained.
-    // Otherwise, the fork is *hostile*, attempting to take control over the
-    // original project's identity. Thus it is recommended to leave the comment
-    // on the following line intact, so that it shows up in code reviews that
-    // modify the field.
-    .fingerprint = 0x934b00cf88f69b22, // Changing this has security and trust implications.
-    // Tracks the earliest Zig version that the package considers to be a
-    // supported use case.
     .minimum_zig_version = "0.16.0",
-    // This field is optional.
+    .dependencies = .{},
-    // Each dependency must either provide a `url` and `hash`, or a `path`.
-    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
-    // Once all dependencies are fetched, `zig build` no longer requires
-    // internet connectivity.
-    .dependencies = .{
-        // See `zig fetch --save <url>` for a command-line interface for adding dependencies.
-        //.example = .{
-        //    // When updating this field to a new URL, be sure to delete the corresponding
-        //    // `hash`, otherwise you are communicating that you expect to find the old hash at
-        //    // the new URL. If the contents of a URL change this will result in a hash mismatch
-        //    // which will prevent zig from using it.
-        //    .url = "https://example.com/foo.tar.gz",
-        //
-        //    // This is computed from the file contents of the directory of files that is
-        //    // obtained after fetching `url` and applying the inclusion rules given by
-        //    // `paths`.
-        //    //
-        //    // This field is the source of truth; packages do not come from a `url`; they
-        //    // come from a `hash`. `url` is just one of many possible mirrors for how to
-        //    // obtain a package matching this `hash`.
-        //    //
-        //    // Uses the [multihash](https://multiformats.io/multihash/) format.
-        //    .hash = "...",
-        //
-        //    // When this is provided, the package is found in a directory relative to the
-        //    // build root. In this case the package's hash is irrelevant and therefore not
-        //    // computed. This field and `url` are mutually exclusive.
-        //    .path = "foo",
-        //
-        //    // When this is set to `true`, a package is declared to be lazily
-        //    // fetched. This makes the dependency only get fetched if it is
-        //    // actually used.
-        //    .lazy = false,
-        //},
-    },
-    // Specifies the set of files and directories that are included in this package.
-    // Only files and directories listed here are included in the `hash` that
-    // is computed for this package. Only files listed here will remain on disk
-    // when using the zig package manager. As a rule of thumb, one should list
-    // files required for compilation plus any license(s).
-    // Paths are relative to the build root. Use the empty string (`""`) to refer to
-    // the build root itself.
-    // A directory listed here means that all files within, recursively, are included.
     .paths = .{
         "build.zig",
         "build.zig.zon",
         "src",
-        // For example...
+        "test_runner.zig",
-        //"LICENSE",
-        //"README.md",
     },
 }

src/Base.zig

@@ -0,0 +1,155 @@
+const std = @import("std");
+
+// Adjust these imports to match your actual file names
+const Dimensions = @import("Dimensions.zig");
+const Scales = @import("Scales.zig");
+const Scalar = @import("Scalar.zig").Scalar;
+
+/// Helper function to create a clean namespace for each physical dimension.
+/// It exposes the raw dimensions, and easy type-creators for Base or Scaled variants.
+pub fn BaseScalar(comptime d: anytype) type {
+    return struct {
+        pub const dims = Dimensions.init(d);
+
+        /// Creates a Scalar of this dimension using default scales.
+        /// Example: const V = Quantities.Velocity.Base(f32);
+        pub fn Of(comptime T: type) type {
+            return Scalar(T, dims, Scales.init(.{}));
+        }
+
+        /// Creates a Scalar of this dimension using custom scales.
+        /// Example: const Kmh = Quantities.Velocity.Scaled(f32, Scales.init(.{ .L = .k, .T = .hour }));
+        pub fn Scaled(comptime T: type, comptime s: Scales) type {
+            return Scalar(T, dims, s);
+        }
+    };
+}
+
+pub const Dimless = BaseScalar(.{});
+
+// ==========================================
+// Base Quantities
+// ==========================================
+pub const Meter = BaseScalar(.{ .L = 1 });
+pub const Second = BaseScalar(.{ .T = 1 });
+pub const Gramm = BaseScalar(.{ .M = 1 });
+pub const Kelvin = BaseScalar(.{ .Tr = 1 });
+pub const ElectricCurrent = BaseScalar(.{ .I = 1 });
+
+// ==========================================
+// Electric
+// ==========================================
+pub const ElectricConductivity = BaseScalar(.{ .M = -1, .L = -3, .T = 3, .I = 2 });
+pub const ElectricCharge = BaseScalar(.{ .T = 1, .I = 1 });
+pub const ElectricPotential = BaseScalar(.{ .T = -3, .L = 2, .M = 1, .I = -1 });
+pub const ElectricResistance = BaseScalar(.{ .M = 1, .L = 2, .T = -3, .I = -2 });
+pub const ElectricResistivity = BaseScalar(.{ .M = 1, .L = 3, .T = -3, .I = -2 });
+pub const ElectricCapacitance = BaseScalar(.{ .T = 4, .L = -2, .M = -1, .I = 2 });
+pub const ElectricImpedance = ElectricResistance;
+pub const MagneticFlux = BaseScalar(.{ .M = 1, .L = 2, .T = -2, .I = -1 });
+pub const MagneticDensity = BaseScalar(.{ .M = 1, .T = -2, .I = -1 });
+pub const MagneticStrength = BaseScalar(.{ .L = -1, .I = 1 }); // Fixed typo from MagneticStrengh
+pub const MagneticMoment = BaseScalar(.{ .L = 2, .I = 1 });
+
+// ==========================================
+// Movement
+// ==========================================
+pub const Speed = BaseScalar(.{ .L = 1, .T = -1 });
+pub const Acceleration = BaseScalar(.{ .L = 1, .T = -2 });
+pub const Inertia = BaseScalar(.{ .M = 1, .L = 2 });
+
+// ==========================================
+// Forces / Energy
+// ==========================================
+pub const Force = BaseScalar(.{ .T = -2, .M = 1, .L = 1 });
+pub const Pressure = BaseScalar(.{ .T = -2, .L = -1, .M = 1 });
+pub const Energy = BaseScalar(.{ .T = -2, .L = 2, .M = 1 });
+pub const Power = BaseScalar(.{ .T = -3, .L = 2, .M = 1 });
+
+// ==========================================
+// Dimension
+// ==========================================
+pub const Area = BaseScalar(.{ .L = 2 });
+pub const Volume = BaseScalar(.{ .L = 3 });
+pub const AreaDensity = BaseScalar(.{ .M = 1, .L = -2 });
+pub const Density = BaseScalar(.{ .M = 1, .L = -3 });
+
+// ==========================================
+// Thermal
+// ==========================================
+pub const ThermalHeat = Energy;
+pub const ThermalWork = Energy;
+pub const ThermalCapacity = BaseScalar(.{ .M = 1, .L = 2, .T = -2, .Tr = -1 });
+pub const ThermalCapacityPerMass = BaseScalar(.{ .L = 2, .T = -2, .Tr = -1 });
+pub const ThermalFluxDensity = BaseScalar(.{ .M = 1, .T = -3 }); // Fixed typo from ThermalluxDensity
+pub const ThermalConductance = BaseScalar(.{ .M = 1, .L = 2, .T = -3, .Tr = -1 });
+pub const ThermalConductivity = BaseScalar(.{ .M = 1, .L = 1, .T = -3, .Tr = -1 });
+pub const ThermalResistance = BaseScalar(.{ .M = -1, .L = -2, .T = 3, .Tr = 1 });
+pub const ThermalResistivity = BaseScalar(.{ .M = -1, .L = -1, .T = 3, .Tr = 1 });
+pub const ThermalEntropy = BaseScalar(.{ .M = 1, .L = 2, .T = -2, .Tr = -1 });
+
+// ==========================================
+// Others
+// ==========================================
+pub const Frequency = BaseScalar(.{ .T = -1 });
+pub const Viscosity = BaseScalar(.{ .M = 1, .L = -1, .T = -1 });
+pub const SurfaceTension = BaseScalar(.{ .M = 1, .T = -2 }); // Corrected from MT-2a
+
+test "BaseQuantities - Core dimensions instantiation" {
+    // Basic types via generic wrappers
+    const M = Meter.Of(f32);
+    const distance = M{ .value = 100.0 };
+    try std.testing.expectEqual(100.0, distance.value);
+    try std.testing.expectEqual(1, M.dims.get(.L));
+    try std.testing.expectEqual(0, M.dims.get(.T));
+
+    // Test specific scale variants
+    const Kmh = Speed.Scaled(f32, Scales.init(.{ .L = .k, .T = .hour }));
+    const speed = Kmh{ .value = 120.0 };
+    try std.testing.expectEqual(120.0, speed.value);
+    try std.testing.expectEqual(.k, @TypeOf(speed).scales.get(.L));
+    try std.testing.expectEqual(.hour, @TypeOf(speed).scales.get(.T));
+}
+
+test "BaseQuantities - Kinematics equations" {
+    const d = Meter.Of(f32){ .value = 50.0 };
+    const t = Second.Of(f32){ .value = 2.0 };
+
+    // Velocity = Distance / Time
+    const v = d.divBy(t);
+    try std.testing.expectEqual(25.0, v.value);
+    try std.testing.expect(Speed.dims.eql(@TypeOf(v).dims));
+
+    // Acceleration = Velocity / Time
+    const a = v.divBy(t);
+    try std.testing.expectEqual(12.5, a.value);
+    try std.testing.expect(Acceleration.dims.eql(@TypeOf(a).dims));
+}
+
+test "BaseQuantities - Dynamics (Force and Work)" {
+    // 10 kg
+    const m = Gramm.Scaled(f32, Scales.init(.{ .M = .k })){ .value = 10.0 };
+    // 9.8 m/s^2
+    const a = Acceleration.Of(f32){ .value = 9.8 };
+
+    // Force = mass * acceleration
+    const f = m.mulBy(a);
+    try std.testing.expectEqual(98000, f.value);
+    try std.testing.expect(Force.dims.eql(@TypeOf(f).dims));
+
+    // Energy (Work) = Force * distance
+    const distance = Meter.Of(f32){ .value = 5.0 };
+    const energy = f.mulBy(distance);
+    try std.testing.expectEqual(490000, energy.value);
+    try std.testing.expect(Energy.dims.eql(@TypeOf(energy).dims));
+}
+
+test "BaseQuantities - Electric combinations" {
+    const current = ElectricCurrent.Of(f32){ .value = 2.0 }; // 2 A
+    const time = Second.Of(f32){ .value = 3.0 }; // 3 s
+
+    // Charge = Current * time
+    const charge = current.mulBy(time);
+    try std.testing.expectEqual(6.0, charge.value);
+    try std.testing.expect(ElectricCharge.dims.eql(@TypeOf(charge).dims));
+}

src/Dimensions.zig

@@ -33,24 +33,24 @@ pub const Dimension = enum {
 
 const Self = @This();
 
-data: std.EnumArray(Dimension, i8),
+data: std.EnumArray(Dimension, comptime_int),
 
 pub fn init(comptime init_val: anytype) Self {
-    var s = Self{ .data = std.EnumArray(Dimension, i8).initFill(0) };
+    var s = Self{ .data = std.EnumArray(Dimension, comptime_int).initFill(0) };
     inline for (std.meta.fields(@TypeOf(init_val))) |f|
         s.data.set(@field(Dimension, f.name), @field(init_val, f.name));
     return s;
 }
 
-pub fn initFill(val: i8) Self {
+pub fn initFill(comptime val: comptime_int) Self {
-    return .{ .data = std.EnumArray(Dimension, i8).initFill(val) };
+    return .{ .data = std.EnumArray(Dimension, comptime_int).initFill(val) };
 }
 
-pub fn get(self: Self, key: Dimension) i8 {
+pub fn get(comptime self: Self, comptime key: Dimension) comptime_int {
     return self.data.get(key);
 }
 
-pub fn set(self: *Self, key: Dimension, val: i8) void {
+pub fn set(comptime self: *Self, comptime key: Dimension, comptime val: i8) void {
     self.data.set(key, val);
 }
 
@@ -64,13 +64,13 @@ pub fn add(comptime a: Self, comptime b: Self) Self {
 pub fn sub(comptime a: Self, comptime b: Self) Self {
     @setEvalBranchQuota(10_000);
     var result = Self.initFill(0);
-    for (std.enums.values(Dimension)) |d|
+    inline for (std.enums.values(Dimension)) |d|
         result.set(d, a.get(d) - b.get(d));
     return result;
 }
 
 pub fn eql(comptime a: Self, comptime b: Self) bool {
-    for (std.enums.values(Dimension)) |d|
+    inline for (std.enums.values(Dimension)) |d|
         if (a.get(d) != b.get(d)) return false;
     return true;
 }

src/Scalar.zig

@@ -0,0 +1,396 @@
+const std = @import("std");
+const hlp = @import("helper.zig");
+
+const Vector = @import("Vector.zig").Vector;
+const Scales = @import("Scales.zig");
+const UnitScale = Scales.UnitScale;
+const Dimensions = @import("Dimensions.zig");
+const Dimension = Dimensions.Dimension;
+
+pub fn Scalar(comptime T: type, comptime d: Dimensions, comptime s: Scales) type {
+    @setEvalBranchQuota(10_000_000);
+    return struct {
+        value: T,
+
+        const Self = @This();
+        pub const Vec3: type = Vector(3, Self);
+        pub const ValueType: type = T;
+
+        pub const dims: Dimensions = d;
+        pub const scales = s;
+
+        pub inline fn add(self: Self, rhs: anytype) Scalar(
+            T,
+            dims,
+            scales.min(@TypeOf(rhs).scales),
+        ) {
+            if (comptime !dims.eql(@TypeOf(rhs).dims))
+                @compileError("Dimension mismatch in add: " ++ dims.str() ++ " vs " ++ @TypeOf(rhs).dims.str());
+            if (comptime @TypeOf(rhs) == Self)
+                return .{ .value = self.value + rhs.value };
+
+            const TargetType = Scalar(T, dims, scales.min(@TypeOf(rhs).scales));
+            const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
+            const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
+
+            return .{ .value = lhs_val + rhs_val };
+        }
+
+        pub inline fn sub(self: Self, rhs: anytype) Scalar(
+            T,
+            dims,
+            scales.min(@TypeOf(rhs).scales),
+        ) {
+            if (comptime !dims.eql(@TypeOf(rhs).dims))
+                @compileError("Dimension mismatch in sub: " ++ dims.str() ++ " vs " ++ @TypeOf(rhs).dims.str());
+            if (comptime @TypeOf(rhs) == Self)
+                return .{ .value = self.value - rhs.value };
+
+            const TargetType = Scalar(T, dims, scales.min(@TypeOf(rhs).scales));
+            const lhs_val = if (comptime @TypeOf(self) == TargetType) self.value else self.to(TargetType).value;
+            const rhs_val = if (comptime @TypeOf(rhs) == TargetType) rhs.value else rhs.to(TargetType).value;
+
+            return .{ .value = lhs_val - rhs_val };
+        }
+
+        pub inline fn mulBy(self: Self, rhs: anytype) Scalar(
+            T,
+            dims.add(@TypeOf(rhs).dims),
+            scales.min(@TypeOf(rhs).scales),
+        ) {
+            const RhsType = @TypeOf(rhs);
+            const SelfNorm = Scalar(T, dims, scales.min(RhsType.scales));
+            const RhsNorm = Scalar(T, RhsType.dims, scales.min(RhsType.scales));
+            if (comptime Self == SelfNorm and RhsType == RhsNorm)
+                return .{ .value = self.value * rhs.value };
+
+            const lhs_val = if (comptime Self == SelfNorm) self.value else self.to(SelfNorm).value;
+            const rhs_val = if (comptime RhsType == RhsNorm) rhs.value else rhs.to(RhsNorm).value;
+            return .{ .value = lhs_val * rhs_val };
+        }
+
+        pub inline fn divBy(self: Self, rhs: anytype) Scalar(
+            T,
+            dims.sub(@TypeOf(rhs).dims),
+            scales.min(@TypeOf(rhs).scales),
+        ) {
+            const RhsType = @TypeOf(rhs);
+            const SelfNorm = Scalar(T, dims, scales.min(RhsType.scales));
+            const RhsNorm = Scalar(T, RhsType.dims, scales.min(RhsType.scales));
+            const lhs_val = if (comptime Self == SelfNorm) self.value else self.to(SelfNorm).value;
+            const rhs_val = if (comptime RhsType == RhsNorm) rhs.value else rhs.to(RhsNorm).value;
+            if (comptime @typeInfo(T) == .int) {
+                return .{ .value = @divTrunc(lhs_val, rhs_val) };
+            } else {
+                return .{ .value = lhs_val / rhs_val };
+            }
+        }
+
+        pub inline fn to(self: Self, comptime Dest: type) Dest {
+            if (comptime !dims.eql(Dest.dims))
+                @compileError("Dimension mismatch in to: " ++ dims.str() ++ " vs " ++ Dest.dims.str());
+            if (comptime @TypeOf(self) == Dest)
+                return self;
+
+            const DestT = Dest.ValueType;
+            const ratio = comptime (scales.getFactor(dims) / Dest.scales.getFactor(Dest.dims));
+
+            // Fast-path: Native pure-integer exact conversions
+            if (comptime @typeInfo(T) == .int and @typeInfo(DestT) == .int) {
+                if (comptime ratio >= 1.0 and @round(ratio) == ratio) {
+                    const mult: DestT = comptime @intFromFloat(ratio);
+                    return .{ .value = @as(DestT, @intCast(self.value)) * mult };
+                } else if (comptime ratio < 1.0 and @round(1.0 / ratio) == 1.0 / ratio) {
+                    const div: DestT = comptime @intFromFloat(1.0 / ratio);
+                    const val = @as(DestT, @intCast(self.value));
+                    const half = comptime div / 2;
+                    // Native round-to-nearest
+                    const rounded = if (val >= 0) @divTrunc(val + half, div) else @divTrunc(val - half, div);
+                    return .{ .value = rounded };
+                }
+            }
+
+            // Fallback preserving native Float types (e.g., f128 shouldn't downcast to f64)
+            if (comptime @typeInfo(DestT) == .float) {
+                const val_f = switch (@typeInfo(T)) {
+                    inline .int => @as(DestT, @floatFromInt(self.value)),
+                    inline .float => @as(DestT, @floatCast(self.value)),
+                    else => unreachable,
+                };
+                return .{ .value = val_f * @as(DestT, @floatCast(ratio)) };
+            } else {
+                const val_f = switch (@typeInfo(T)) {
+                    inline .int => @as(f64, @floatFromInt(self.value)),
+                    inline .float => @as(f64, @floatCast(self.value)),
+                    else => unreachable,
+                };
+                return .{ .value = @intFromFloat(@round(val_f * ratio)) };
+            }
+        }
+
+        pub fn Vec(self: Self, comptime len: comptime_int) Vector(len, Self) {
+            return Vector(len, Self).initDefault(self.value);
+        }
+
+        pub fn vec3(self: Self) Vec3 {
+            return Vec3.initDefault(self.value);
+        }
+
+        pub fn formatNumber(
+            self: Self,
+            writer: *std.Io.Writer,
+            options: std.fmt.Number,
+        ) !void {
+            switch (@typeInfo(T)) {
+                .float, .comptime_float => try writer.printFloat(self.value, options),
+                .int, .comptime_int => try writer.printInt(self.value, 10, .lower, .{
+                    .width = options.width,
+                    .alignment = options.alignment,
+                    .fill = options.fill,
+                    .precision = options.precision,
+                }),
+                else => unreachable,
+            }
+            var first = true;
+            inline for (std.enums.values(Dimension)) |bu| {
+                const v = dims.get(bu);
+                if (comptime v == 0) continue;
+                if (!first)
+                    try writer.writeAll(".");
+
+                first = false;
+
+                const uscale = scales.get(bu);
+                if (bu == .T and (uscale == .min or uscale == .hour or uscale == .year))
+                    try writer.print("{s}", .{uscale.str()})
+                else
+                    try writer.print("{s}{s}", .{ uscale.str(), bu.unit() });
+
+                if (v != 1)
+                    try hlp.printSuperscript(writer, v);
+            }
+        }
+    };
+}
+
+test "Generate quantity" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = -3 }));
+    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .n }));
+
+    const distance = Meter{ .value = 10 };
+    const time = Second{ .value = 2 };
+
+    try std.testing.expectEqual(10, distance.value);
+    try std.testing.expectEqual(2, time.value);
+}
+
+test "Add" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    const distance = Meter{ .value = 10 };
+    const distance2 = Meter{ .value = 20 };
+
+    const added = distance.add(distance2);
+    try std.testing.expectEqual(30, added.value);
+    try std.testing.expectEqual(1, @TypeOf(added).dims.get(.L));
+
+    const KiloMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const distance3 = KiloMeter{ .value = 2 };
+    const added2 = distance.add(distance3);
+    try std.testing.expectEqual(2010, added2.value);
+    try std.testing.expectEqual(1, @TypeOf(added2).dims.get(.L));
+
+    const added3 = distance3.add(distance).to(KiloMeter);
+    try std.testing.expectEqual(2, added3.value);
+    try std.testing.expectEqual(1, @TypeOf(added3).dims.get(.L));
+
+    const KiloMeter_f = Scalar(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const distance4 = KiloMeter_f{ .value = 2 };
+    const added4 = distance4.add(distance).to(KiloMeter_f);
+    try std.testing.expectApproxEqAbs(2.01, added4.value, 0.000001);
+    try std.testing.expectEqual(1, @TypeOf(added4).dims.get(.L));
+}
+
+test "Sub" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const KiloMeter_f = Scalar(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+
+    const a = Meter{ .value = 500 };
+    const b = Meter{ .value = 200 };
+    const diff = a.sub(b);
+    try std.testing.expectEqual(300, diff.value);
+    const diff2 = b.sub(a);
+    try std.testing.expectEqual(-300, diff2.value);
+
+    const km_f = KiloMeter_f{ .value = 2.5 };
+    const m_f = Meter{ .value = 500 };
+    const diff3 = km_f.sub(m_f);
+    try std.testing.expectApproxEqAbs(2000, diff3.value, 1e-4);
+}
+
+test "MulBy" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+
+    const d = Meter{ .value = 3.0 };
+    const t = Second{ .value = 4.0 };
+
+    const area_time = d.mulBy(t);
+    try std.testing.expectEqual(12, area_time.value);
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
+
+    const d2 = Meter{ .value = 5.0 };
+    const area = d.mulBy(d2);
+    try std.testing.expectEqual(15, area.value);
+    try std.testing.expectEqual(2, @TypeOf(area).dims.get(.L));
+    try std.testing.expectEqual(0, @TypeOf(area).dims.get(.T));
+}
+
+test "MulBy with scale" {
+    const KiloMeter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const KiloGram = Scalar(f32, Dimensions.init(.{ .M = 1 }), Scales.init(.{ .M = .k }));
+
+    const dist = KiloMeter{ .value = 2.0 };
+    const mass = KiloGram{ .value = 3.0 };
+    const prod = dist.mulBy(mass);
+    try std.testing.expectEqual(1, @TypeOf(prod).dims.get(.L));
+    try std.testing.expectEqual(1, @TypeOf(prod).dims.get(.M));
+}
+
+test "MulBy with type change" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Second = Scalar(f64, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const KmSec = Scalar(i64, Dimensions.init(.{ .L = 1, .T = 1 }), Scales.init(.{ .L = .k }));
+    const KmSec_f = Scalar(f32, Dimensions.init(.{ .L = 1, .T = 1 }), Scales.init(.{ .L = .k }));
+
+    const d = Meter{ .value = 3.0 };
+    const t = Second{ .value = 4.0 };
+
+    const area_time = d.mulBy(t).to(KmSec);
+    const area_time_f = d.mulBy(t).to(KmSec_f);
+    try std.testing.expectEqual(12, area_time.value);
+    try std.testing.expectApproxEqAbs(12, area_time_f.value, 0.0001);
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
+}
+
+test "MulBy small" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .n }));
+    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+
+    const d = Meter{ .value = 3.0 };
+    const t = Second{ .value = 4.0 };
+
+    const area_time = d.mulBy(t);
+    try std.testing.expectEqual(12, area_time.value);
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
+    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
+}
+
+test "MulBy dimensionless" {
+    const DimLess = Scalar(i128, Dimensions.init(.{}), Scales.init(.{}));
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    const d = Meter{ .value = 7 };
+    const scaled = d.mulBy(DimLess{ .value = 3 });
+    try std.testing.expectEqual(21, scaled.value);
+    try std.testing.expectEqual(1, @TypeOf(scaled).dims.get(.L));
+}
+
+test "Chained: velocity and acceleration" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+
+    const dist = Meter{ .value = 100.0 };
+    const t1 = Second{ .value = 5.0 };
+    const velocity = dist.divBy(t1);
+    try std.testing.expectEqual(20, velocity.value);
+    try std.testing.expectEqual(1, @TypeOf(velocity).dims.get(.L));
+    try std.testing.expectEqual(-1, @TypeOf(velocity).dims.get(.T));
+
+    const t2 = Second{ .value = 4.0 };
+    const accel = velocity.divBy(t2);
+    try std.testing.expectEqual(5, accel.value);
+    try std.testing.expectEqual(1, @TypeOf(accel).dims.get(.L));
+    try std.testing.expectEqual(-2, @TypeOf(accel).dims.get(.T));
+}
+
+test "DivBy integer exact" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Second = Scalar(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+
+    const dist = Meter{ .value = 120 };
+    const time = Second{ .value = 4 };
+    const vel = dist.divBy(time);
+
+    try std.testing.expectEqual(30, vel.value);
+    try std.testing.expectEqual(1, @TypeOf(vel).dims.get(.L));
+    try std.testing.expectEqual(-1, @TypeOf(vel).dims.get(.T));
+}
+
+test "Conversion chain: km -> m -> cm" {
+    const KiloMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const CentiMeter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .c }));
+
+    const km = KiloMeter{ .value = 15 };
+    const m = km.to(Meter);
+    const cm = m.to(CentiMeter);
+
+    try std.testing.expectEqual(15_000, m.value);
+    try std.testing.expectEqual(1_500_000, cm.value);
+}
+
+test "Conversion: hours -> minutes -> seconds" {
+    const Hour = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .hour }));
+    const Minute = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .min }));
+    const Second = Scalar(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+
+    const h = Hour{ .value = 1.0 };
+    const min = h.to(Minute);
+    const sec = min.to(Second);
+
+    try std.testing.expectEqual(60, min.value);
+    try std.testing.expectEqual(3600, sec.value);
+}
+
+test "Negative values" {
+    const Meter = Scalar(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    const a = Meter{ .value = 5 };
+    const b = Meter{ .value = 20 };
+    const diff = a.sub(b);
+    try std.testing.expectEqual(-15, diff.value);
+}
+
+test "Format Scalar" {
+    const MeterPerSecondSq = Scalar(
+        f32,
+        Dimensions.init(.{ .L = 1, .T = -2 }),
+        Scales.init(.{ .T = .n }),
+    );
+    const KgMeterPerSecond = Scalar(
+        f32,
+        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
+        Scales.init(.{ .M = .k }),
+    );
+    const Meter = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    const m = Meter{ .value = 1.23456 };
+    const accel = MeterPerSecondSq{ .value = 9.81 };
+    const momentum = KgMeterPerSecond{ .value = 42.0 };
+
+    var buf: [64]u8 = undefined;
+    var res = try std.fmt.bufPrint(&buf, "{d:.2}", .{m});
+    try std.testing.expectEqualStrings("1.23m", res);
+
+    res = try std.fmt.bufPrint(&buf, "{d}", .{accel});
+    try std.testing.expectEqualStrings("9.81m.ns⁻²", res);
+
+    res = try std.fmt.bufPrint(&buf, "{d}", .{momentum});
+    try std.testing.expectEqualStrings("42m.kg.s⁻¹", res);
+
+    res = try std.fmt.bufPrint(&buf, "{d:_>10.1}", .{m});
+    try std.testing.expectEqualStrings("_______1.2m", res);
+}

src/Scales.zig

@@ -3,7 +3,7 @@ const hlp = @import("helper.zig");
 const Dimensions = @import("Dimensions.zig");
 const Dimension = @import("Dimensions.zig").Dimension;
 
-pub const UnitScale = enum(i32) {
+pub const UnitScale = enum(isize) {
     P = 15,
     T = 12,
     G = 9,
@@ -28,28 +28,28 @@ pub const UnitScale = enum(i32) {
     // Undefined
     _,
 
-    pub fn str(self: @This()) []const u8 {
+    pub inline fn str(self: @This()) []const u8 {
         var buf: [16]u8 = undefined;
         return switch (self) {
-            .none => "",
+            inline .none => "",
             inline .P, .T, .G, .M, .k, .h, .da, .d, .c, .m, .u, .n, .p, .f, .min, .hour, .year => @tagName(self),
-            else => std.fmt.bufPrint(&buf, "[{d}]", .{@intFromEnum(self)}) catch "[]",
+            else => std.fmt.bufPrint(&buf, "[{d}]", .{@intFromEnum(self)}) catch "[]", // This cannot be inline because of non exhaustive enum, but that's ok, it is just str, not calculation
         };
     }
 
     /// Helper to get the actual scaling factor
-    pub fn getFactor(self: @This()) f64 {
+    pub inline fn getFactor(self: @This()) comptime_float {
         return switch (self) {
             inline .P, .T, .G, .M, .k, .h, .da, .none, .d, .c, .m, .u, .n, .p, .f => std.math.pow(f64, 10.0, @floatFromInt(@intFromEnum(self))),
-            else => @floatFromInt(@intFromEnum(self)),
+            inline else => @floatFromInt(@intFromEnum(self)),
         };
     }
 
     /// Helper to get the actual scaling factor in i32
-    pub fn getFactorInt(self: @This()) i32 {
+    pub inline fn getFactorInt(self: @This()) comptime_int {
         return switch (self) {
-            inline .P, .T, .G, .M, .k, .h, .da, .none, .d, .c, .m, .u, .n, .p, .f => std.math.powi(i32, 10.0, @intFromEnum(self)) catch 0,
+            inline .P, .T, .G, .M, .k, .h, .da, .none, .d, .c, .m, .u, .n, .p, .f => comptime std.math.powi(i32, 10.0, @intFromEnum(self)) catch 0,
-            else => @intFromEnum(self),
+            inline else => comptime @intFromEnum(self),
         };
     }
 };
@@ -59,7 +59,7 @@ const Scales = @This();
 data: std.EnumArray(Dimension, UnitScale),
 
 pub fn init(comptime init_val: anytype) Scales {
-    var s = Scales{ .data = std.EnumArray(Dimension, UnitScale).initFill(.none) };
+    comptime var s = Scales{ .data = std.EnumArray(Dimension, UnitScale).initFill(.none) };
     inline for (std.meta.fields(@TypeOf(init_val))) |f| {
         if (comptime hlp.isInt(@TypeOf(@field(init_val, f.name))))
             s.data.set(@field(Dimension, f.name), @enumFromInt(@field(init_val, f.name)))
@@ -69,29 +69,29 @@ pub fn init(comptime init_val: anytype) Scales {
     return s;
 }
 
-pub fn initFill(val: UnitScale) Scales {
+pub fn initFill(comptime val: UnitScale) Scales {
-    return .{ .data = std.EnumArray(Dimension, UnitScale).initFill(val) };
+    return comptime .{ .data = std.EnumArray(Dimension, UnitScale).initFill(val) };
 }
 
-pub fn get(self: Scales, key: Dimension) UnitScale {
+pub fn get(comptime self: Scales, comptime key: Dimension) UnitScale {
-    return self.data.get(key);
+    return comptime self.data.get(key);
 }
 
-pub fn set(self: *Scales, key: Dimension, val: UnitScale) void {
+pub fn set(comptime self: *Scales, comptime key: Dimension, comptime val: UnitScale) void {
-    self.data.set(key, val);
+    comptime self.data.set(key, val);
 }
 
 pub fn min(comptime s1: Scales, comptime s2: Scales) Scales {
-    var out = Scales.initFill(.none);
+    comptime var out = Scales.initFill(.none);
-    for (std.enums.values(Dimension)) |dim|
+    inline for (std.enums.values(Dimension)) |dim|
         out.set(dim, if (s1.get(dim).getFactorInt() > s2.get(dim).getFactorInt()) s2.get(dim) else s1.get(dim));
 
     return out;
 }
 
-pub fn getFactor(comptime s: Scales, comptime d: Dimensions) f64 {
+pub inline fn getFactor(comptime s: Scales, comptime d: Dimensions) comptime_float {
-    var factor: f64 = 1.0;
+    comptime var factor: f64 = 1.0;
-    for (std.enums.values(Dimension)) |dim| {
+    inline for (std.enums.values(Dimension)) |dim| {
         const power = d.get(dim);
         if (power == 0) continue;
 

src/Vector.zig

@@ -0,0 +1,318 @@
+const std = @import("std");
+const hlp = @import("helper.zig");
+
+const Scalar = @import("Scalar.zig").Scalar;
+const Scales = @import("Scales.zig");
+const UnitScale = Scales.UnitScale;
+const Dimensions = @import("Dimensions.zig");
+const Dimension = Dimensions.Dimension;
+
+pub fn Vector(comptime len: usize, comptime Q: type) type {
+    const T = Q.ValueType;
+    const d: Dimensions = Q.dims;
+    const s: Scales = Q.scales;
+
+    return struct {
+        data: [len]T,
+
+        const Self = @This();
+        pub const ScalarType = Q;
+        pub const ValueType = T;
+        pub const dims: Dimensions = d;
+        pub const scales = s;
+
+        pub const zero = initDefault(0);
+        pub const one = initDefault(1);
+
+        pub fn initDefault(v: T) Self {
+            var data: [len]T = undefined;
+            inline for (&data) |*item| item.* = v;
+            return .{ .data = data };
+        }
+
+        pub inline fn add(self: Self, rhs: anytype) Vector(len, Scalar(T, d, s.min(@TypeOf(rhs).scales))) {
+            const Tr = @TypeOf(rhs);
+            var res: Vector(len, Scalar(T, d, s.min(Tr.scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = (Q{ .value = v }).add(Tr.ScalarType{ .value = rhs.data[i] });
+                res.data[i] = q.value;
+            }
+            return res;
+        }
+
+        pub inline fn sub(self: Self, rhs: anytype) Vector(len, Scalar(T, d, s.min(@TypeOf(rhs).scales))) {
+            const Tr = @TypeOf(rhs);
+            var res: Vector(len, Scalar(T, d, s.min(Tr.scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = (Q{ .value = v }).sub(Tr.ScalarType{ .value = rhs.data[i] });
+                res.data[i] = q.value;
+            }
+            return res;
+        }
+
+        pub inline fn divBy(
+            self: Self,
+            rhs: anytype,
+        ) Vector(len, Scalar(T, d.sub(@TypeOf(rhs).dims), s.min(@TypeOf(rhs).scales))) {
+            const Tr = @TypeOf(rhs);
+            var res: Vector(len, Scalar(T, d.sub(Tr.dims), s.min(Tr.scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = (Q{ .value = v }).divBy(Tr.ScalarType{ .value = rhs.data[i] });
+                res.data[i] = q.value;
+            }
+            return res;
+        }
+
+        pub inline fn mulBy(
+            self: Self,
+            rhs: anytype,
+        ) Vector(len, Scalar(T, d.add(@TypeOf(rhs).dims), s.min(@TypeOf(rhs).scales))) {
+            const Tr = @TypeOf(rhs);
+            var res: Vector(len, Scalar(T, d.add(Tr.dims), s.min(Tr.scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = (Q{ .value = v }).mulBy(Tr.ScalarType{ .value = rhs.data[i] });
+                res.data[i] = q.value;
+            }
+            return res;
+        }
+
+        pub inline fn divByScalar(
+            self: Self,
+            scalar: anytype,
+        ) Vector(len, Scalar(T, d.sub(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) {
+            var res: Vector(len, Scalar(T, d.sub(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = Q{ .value = v };
+                res.data[i] = q.divBy(scalar).value;
+            }
+            return res;
+        }
+
+        pub inline fn mulByScalar(
+            self: Self,
+            scalar: anytype,
+        ) Vector(len, Scalar(T, d.add(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) {
+            var res: Vector(len, Scalar(T, d.add(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                const q = Q{ .value = v };
+                res.data[i] = q.mulBy(scalar).value;
+            }
+            return res;
+        }
+
+        pub fn negate(self: Self) Self {
+            var res: Self = undefined;
+            inline for (self.data, 0..) |v, i| {
+                res.data[i] = -v;
+            }
+            return res;
+        }
+
+        pub inline fn to(self: Self, comptime DestQ: type) Vector(len, DestQ) {
+            var res: Vector(len, DestQ) = undefined;
+            inline for (self.data, 0..) |v, i| {
+                res.data[i] = (Q{ .value = v }).to(DestQ).value;
+            }
+            return res;
+        }
+
+        pub inline fn lengthSqr(self: Self) T {
+            var sum: T = 0;
+            inline for (self.data) |v| {
+                sum += v * v;
+            }
+            return sum;
+        }
+
+        pub inline fn length(self: Self) T {
+            const len_sq = self.lengthSqr();
+
+            if (comptime @typeInfo(T) == .int) {
+                // Construct the unsigned equivalent of T at comptime (e.g., i32 -> u32)
+                const UnsignedT = @Int(.unsigned, @typeInfo(T).int.bits);
+
+                // len_sq is always positive, so @intCast is perfectly safe
+                const u_len_sq = @as(UnsignedT, @intCast(len_sq));
+                return @as(T, @intCast(std.math.sqrt(u_len_sq)));
+            } else {
+                return @sqrt(len_sq);
+            }
+        }
+
+        pub fn formatNumber(
+            self: Self,
+            writer: *std.Io.Writer,
+            options: std.fmt.Number,
+        ) !void {
+            try writer.writeAll("(");
+            for (self.data, 0..) |v, i| {
+                if (i > 0) try writer.writeAll(", ");
+                switch (@typeInfo(T)) {
+                    .float, .comptime_float => try writer.printFloat(v, options),
+                    .int, .comptime_int => try writer.printInt(v, 10, .lower, .{
+                        .width = options.width,
+                        .alignment = options.alignment,
+                        .fill = options.fill,
+                        .precision = options.precision,
+                    }),
+                    else => unreachable,
+                }
+            }
+            try writer.writeAll(")");
+            var first = true;
+            inline for (std.enums.values(Dimension)) |bu| {
+                const v = dims.get(bu);
+                if (comptime v == 0) continue;
+                if (!first)
+                    try writer.writeAll(".");
+
+                first = false;
+
+                const uscale = scales.get(bu);
+                if (bu == .T and (uscale == .min or uscale == .hour or uscale == .year))
+                    try writer.print("{s}", .{uscale.str()})
+                else
+                    try writer.print("{s}{s}", .{ uscale.str(), bu.unit() });
+
+                if (v != 1)
+                    try hlp.printSuperscript(writer, v);
+            }
+        }
+    };
+}
+
+test "Format VectorX" {
+    const MeterPerSecondSq = Scalar(
+        f32,
+        Dimensions.init(.{ .L = 1, .T = -2 }),
+        Scales.init(.{ .T = .n }),
+    );
+    const KgMeterPerSecond = Scalar(
+        f32,
+        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
+        Scales.init(.{ .M = .k }),
+    );
+
+    const accel = MeterPerSecondSq.Vec3.initDefault(9.81);
+    const momentum = KgMeterPerSecond.Vec3{ .data = .{ 43, 0, 11 } };
+
+    var buf: [64]u8 = undefined;
+    var res = try std.fmt.bufPrint(&buf, "{d}", .{accel});
+    try std.testing.expectEqualStrings("(9.81, 9.81, 9.81)m.ns⁻²", res);
+
+    res = try std.fmt.bufPrint(&buf, "{d:.2}", .{momentum});
+    try std.testing.expectEqualStrings("(43.00, 0.00, 11.00)m.kg.s⁻¹", res);
+}
+
+test "VecX Init and Basic Arithmetic" {
+    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Vec3M = Meter.Vec3;
+
+    // Test zero, one, initDefault
+    const v_zero = Vec3M.zero;
+    try std.testing.expectEqual(0, v_zero.data[0]);
+    try std.testing.expectEqual(0, v_zero.data[1]);
+    try std.testing.expectEqual(0, v_zero.data[2]);
+
+    const v_one = Vec3M.one;
+    try std.testing.expectEqual(1, v_one.data[0]);
+    try std.testing.expectEqual(1, v_one.data[1]);
+    try std.testing.expectEqual(1, v_one.data[2]);
+
+    const v_def = Vec3M.initDefault(5);
+    try std.testing.expectEqual(5, v_def.data[0]);
+    try std.testing.expectEqual(5, v_def.data[1]);
+    try std.testing.expectEqual(5, v_def.data[2]);
+
+    // Test add and sub
+    const v1 = Vec3M{ .data = .{ 10, 20, 30 } };
+    const v2 = Vec3M{ .data = .{ 2, 4, 6 } };
+
+    const added = v1.add(v2);
+    try std.testing.expectEqual(12, added.data[0]);
+    try std.testing.expectEqual(24, added.data[1]);
+    try std.testing.expectEqual(36, added.data[2]);
+
+    const subbed = v1.sub(v2);
+    try std.testing.expectEqual(8, subbed.data[0]);
+    try std.testing.expectEqual(16, subbed.data[1]);
+    try std.testing.expectEqual(24, subbed.data[2]);
+
+    // Test negate
+    const neg = v1.negate();
+    try std.testing.expectEqual(-10, neg.data[0]);
+    try std.testing.expectEqual(-20, neg.data[1]);
+    try std.testing.expectEqual(-30, neg.data[2]);
+}
+
+test "VecX Kinematics (Scalar Mul/Div)" {
+    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Second = Scalar(i32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
+    const Vec3M = Meter.Vec3;
+
+    const pos = Vec3M{ .data = .{ 100, 200, 300 } };
+    const time = Second{ .value = 10 };
+
+    // Vector divided by scalar (Velocity = Position / Time)
+    const vel = pos.divByScalar(time);
+    try std.testing.expectEqual(10, vel.data[0]);
+    try std.testing.expectEqual(20, vel.data[1]);
+    try std.testing.expectEqual(30, vel.data[2]);
+    try std.testing.expectEqual(1, @TypeOf(vel).dims.get(.L));
+    try std.testing.expectEqual(-1, @TypeOf(vel).dims.get(.T));
+
+    // Vector multiplied by scalar (Position = Velocity * Time)
+    const new_pos = vel.mulByScalar(time);
+    try std.testing.expectEqual(100, new_pos.data[0]);
+    try std.testing.expectEqual(200, new_pos.data[1]);
+    try std.testing.expectEqual(300, new_pos.data[2]);
+    try std.testing.expectEqual(1, @TypeOf(new_pos).dims.get(.L));
+    try std.testing.expectEqual(0, @TypeOf(new_pos).dims.get(.T));
+}
+
+test "VecX Element-wise Math and Scaling" {
+    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const Vec3M = Meter.Vec3;
+
+    const v1 = Vec3M{ .data = .{ 10, 20, 30 } };
+    const v2 = Vec3M{ .data = .{ 2, 5, 10 } };
+
+    // Element-wise division
+    const div = v1.divBy(v2);
+    try std.testing.expectEqual(5, div.data[0]);
+    try std.testing.expectEqual(4, div.data[1]);
+    try std.testing.expectEqual(3, div.data[2]);
+    try std.testing.expectEqual(0, @TypeOf(div).dims.get(.L)); // M / M = Dimensionless
+}
+
+test "VecX Conversions" {
+    const KiloMeter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
+    const Meter = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    const v_km = KiloMeter.Vec3{ .data = .{ 1, 2, 3 } };
+    const v_m = v_km.to(Meter);
+
+    try std.testing.expectEqual(1000, v_m.data[0]);
+    try std.testing.expectEqual(2000, v_m.data[1]);
+    try std.testing.expectEqual(3000, v_m.data[2]);
+
+    // Type checking the result
+    try std.testing.expectEqual(1, @TypeOf(v_m).dims.get(.L));
+    try std.testing.expectEqual(UnitScale.none, @TypeOf(v_m).scales.get(.L));
+}
+
+test "VecX Length" {
+    const MeterInt = Scalar(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+    const MeterFloat = Scalar(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
+
+    // Integer length (using your custom isqrt)
+    // 3-4-5 triangle on XY plane
+    const v_int = MeterInt.Vec3{ .data = .{ 3, 4, 0 } };
+    try std.testing.expectEqual(25, v_int.lengthSqr());
+    try std.testing.expectEqual(5, v_int.length());
+
+    // Float length
+    const v_float = MeterFloat.Vec3{ .data = .{ 3.0, 4.0, 0.0 } };
+    try std.testing.expectApproxEqAbs(@as(f32, 25.0), v_float.lengthSqr(), 1e-4);
+    try std.testing.expectApproxEqAbs(@as(f32, 5.0), v_float.length(), 1e-4);
+}

src/benchmark.zig

@@ -0,0 +1,429 @@
+const std = @import("std");
+const Io = std.Io;
+const Scalar = @import("Scalar.zig").Scalar;
+const Vector = @import("Vector.zig").Vector;
+
+var io: Io = undefined;
+pub fn main(init: std.process.Init) !void {
+    var stdout_buf: [4096]u8 = undefined;
+    var stdout_writer: std.Io.File.Writer = .init(.stdout(), init.io, &stdout_buf);
+    try stdout_writer.interface.print("Starting Benchmarks...", .{});
+
+    io = init.io;
+
+    try bench_Scalar(&stdout_writer.interface);
+    try stdout_writer.flush();
+    try bench_vsNative(&stdout_writer.interface);
+    try stdout_writer.flush();
+    try bench_crossTypeVsNative(&stdout_writer.interface);
+    try stdout_writer.flush();
+    try bench_Vector(&stdout_writer.interface);
+    try stdout_writer.flush();
+}
+
+fn getTime() Io.Timestamp {
+    return Io.Clock.awake.now(io);
+}
+
+fn fold(comptime TT: type, s: *f64, v: TT) void {
+    s.* += if (comptime @typeInfo(TT) == .float)
+        @as(f64, @floatCast(v))
+    else
+        @as(f64, @floatFromInt(v));
+}
+
+fn bench_Scalar(writer: *std.Io.Writer) !void {
+    const ITERS: usize = 100_000;
+    const SAMPLES: usize = 10;
+
+    const getVal = struct {
+        fn f(comptime TT: type, i: usize, comptime mask: u7) TT {
+            const v: u8 = @as(u8, @truncate(i & @as(usize, mask))) + 1;
+            return if (comptime @typeInfo(TT) == .float) @floatFromInt(v) else @intCast(v);
+        }
+    }.f;
+
+    const Stats = struct {
+        median: f64,
+        delta: f64,
+        ops_per_sec: f64,
+    };
+
+    const computeStats = struct {
+        fn f(samples: []f64, iters: usize) Stats {
+            std.mem.sort(f64, samples, {}, std.sort.asc(f64));
+            const mid = samples.len / 2;
+            const median_ns = if (samples.len % 2 == 0) (samples[mid - 1] + samples[mid]) / 2.0 else samples[mid];
+
+            const low = samples[0];
+            const high = samples[samples.len - 1];
+            const delta_ns = (high - low) / 2.0;
+
+            const ns_per_op = median_ns / @as(f64, @floatFromInt(iters));
+            return .{
+                .median = ns_per_op,
+                .delta = (delta_ns / @as(f64, @floatFromInt(iters))),
+                .ops_per_sec = 1_000_000_000.0 / ns_per_op,
+            };
+        }
+    }.f;
+
+    try writer.print(
+        \\
+        \\ Scalar<T> benchmark — {d} iterations, {d} samples/cell
+        \\
+        \\┌───────────────────┬──────┬─────────────────────┬─────────────────────┐
+        \\│ Operation         │ Type │ ns / op (± delta)   │ Throughput (ops/s)  │
+        \\├───────────────────┼──────┼─────────────────────┼─────────────────────┤
+        \\
+    , .{ ITERS, SAMPLES });
+
+    const Types = .{ i16, i32, i64, i128, i256, f32, f64, f128 };
+    const TNames = .{ "i16", "i32", "i64", "i128", "i256", "f32", "f64", "f128" };
+    const Ops = .{ "add", "sub", "mulBy", "divBy", "to" };
+
+    var results_matrix: [Ops.len][Types.len]f64 = undefined;
+
+    comptime var tidx: usize = 0;
+    inline for (Types, TNames) |T, tname| {
+        const M = Scalar(T, .init(.{ .L = 1 }), .init(.{}));
+        const KM = Scalar(T, .init(.{ .L = 1 }), .init(.{ .L = .k }));
+        const S = Scalar(T, .init(.{ .T = 1 }), .init(.{}));
+
+        inline for (Ops, 0..) |op_name, oidx| {
+            var samples: [SAMPLES]f64 = undefined;
+
+            for (0..SAMPLES) |s_idx| {
+                const t_start = getTime();
+
+                for (0..ITERS) |i| {
+                    std.mem.doNotOptimizeAway(
+                        {
+                            _ = if (comptime std.mem.eql(u8, op_name, "add"))
+                                (M{ .value = getVal(T, i, 63) }).add(M{ .value = getVal(T, i +% 7, 63) })
+                            else if (comptime std.mem.eql(u8, op_name, "sub"))
+                                (M{ .value = getVal(T, i +% 10, 63) }).sub(M{ .value = getVal(T, i, 63) })
+                            else if (comptime std.mem.eql(u8, op_name, "mulBy"))
+                                (M{ .value = getVal(T, i, 63) }).mulBy(M{ .value = getVal(T, i +% 1, 63) })
+                            else if (comptime std.mem.eql(u8, op_name, "divBy"))
+                                (M{ .value = getVal(T, i +% 10, 63) }).divBy(S{ .value = getVal(T, i, 63) })
+                            else
+                                (KM{ .value = getVal(T, i, 15) }).to(M);
+                        },
+                    );
+                }
+
+                const t_end = getTime();
+                samples[s_idx] = @as(f64, @floatFromInt(t_start.durationTo(t_end).toNanoseconds()));
+            }
+
+            const stats = computeStats(&samples, ITERS);
+            results_matrix[oidx][tidx] = stats.median;
+
+            try writer.print("│ {s:<17} │ {s:<4} │ {d:>8.2} ns ±{d:<6.2} │ {d:>19.0} │\n", .{ op_name, tname, stats.median, stats.delta, stats.ops_per_sec });
+        }
+
+        if (comptime tidx < Types.len - 1) {
+            try writer.print("├───────────────────┼──────┼─────────────────────┼─────────────────────┤\n", .{});
+        }
+        tidx += 1;
+    }
+
+    // Median Summary Table
+    try writer.print("└───────────────────┴──────┴─────────────────────┴─────────────────────┘\n\n", .{});
+    try writer.print("Median Summary (ns/op):\n", .{});
+
+    try writer.print("┌──────────────┬───────┬───────┬───────┬───────┬───────┬───────┬───────┬───────┐\n", .{});
+    try writer.print("│  Operation   │  i16  │  i32  │  i64  │  i128 │  i256 │  f32  │  f64  │  f128 │\n", .{});
+    try writer.print("├──────────────┼───────┼───────┼───────┼───────┼───────┼───────┼───────┼───────┤\n", .{});
+
+    inline for (Ops, 0..) |op_name, oidx| {
+        try writer.print("│  {s:<11} │", .{op_name});
+        var i: usize = 0;
+        while (i < Types.len) : (i += 1)
+            try writer.print("{d:>6.1} │", .{results_matrix[oidx][i]});
+
+        try writer.print("\n", .{});
+    }
+
+    try writer.print("└──────────────┴───────┴───────┴───────┴───────┴───────┴───────┴───────┴───────┘\n", .{});
+}
+
+fn bench_vsNative(writer: *std.Io.Writer) !void {
+    const ITERS: usize = 100_000;
+    const SAMPLES: usize = 5;
+
+    // Helper to safely get a value of type T from a loop index
+    const getValT = struct {
+        fn f(comptime TT: type, i: usize) TT {
+            const v = (i % 100) + 1;
+            return if (comptime @typeInfo(TT) == .float) @floatFromInt(v) else @intCast(v);
+        }
+    }.f;
+
+    const Types = .{ i32, i64, i128, f32, f64 };
+    const TNames = .{ "i32", "i64", "i128", "f32", "f64" };
+    const Ops = .{ "add", "mulBy", "divBy" };
+
+    try writer.print(
+        \\
+        \\ Scalar vs Native Overhead Analysis
+        \\
+        \\┌───────────┬──────┬───────────┬───────────┬───────────┐
+        \\│ Operation │ Type │ Native    │ Scalar    │ Slowdown  │
+        \\├───────────┼──────┼───────────┼───────────┼───────────┤
+        \\
+    , .{});
+
+    inline for (Ops, 0..) |op_name, j| {
+        inline for (Types, 0..) |T, tidx| {
+            var native_total_ns: f64 = 0;
+            var quantity_total_ns: f64 = 0;
+
+            const M = Scalar(T, .init(.{ .L = 1 }), .init(.{}));
+            const S = Scalar(T, .init(.{ .T = 1 }), .init(.{}));
+
+            std.mem.doNotOptimizeAway({
+                for (0..SAMPLES) |_| {
+                    // --- 1. Benchmark Native ---
+                    const n_start = getTime();
+                    for (0..ITERS) |i| {
+                        const a = getValT(T, i);
+                        const b = getValT(T, 2);
+                        _ = if (comptime std.mem.eql(u8, op_name, "add"))
+                            a + b
+                        else if (comptime std.mem.eql(u8, op_name, "mulBy"))
+                            a * b
+                        else if (comptime @typeInfo(T) == .int) @divTrunc(a, b) else a / b;
+                    }
+                    const n_end = getTime();
+                    native_total_ns += @as(f64, @floatFromInt(n_start.durationTo(n_end).toNanoseconds()));
+
+                    // --- 2. Benchmark Scalar ---
+                    const q_start = getTime();
+                    for (0..ITERS) |i| {
+                        const qa = M{ .value = getValT(T, i) };
+                        const qb = if (comptime std.mem.eql(u8, op_name, "divBy")) S{ .value = getValT(T, 2) } else M{ .value = getValT(T, 2) };
+
+                        _ = if (comptime std.mem.eql(u8, op_name, "add"))
+                            qa.add(qb)
+                        else if (comptime std.mem.eql(u8, op_name, "mulBy"))
+                            qa.mulBy(qb)
+                        else
+                            qa.divBy(qb);
+                    }
+                    const q_end = getTime();
+                    quantity_total_ns += @as(f64, @floatFromInt(q_start.durationTo(q_end).toNanoseconds()));
+                }
+            });
+
+            const avg_n = (native_total_ns / SAMPLES) / @as(f64, @floatFromInt(ITERS));
+            const avg_q = (quantity_total_ns / SAMPLES) / @as(f64, @floatFromInt(ITERS));
+            const slowdown = avg_q / avg_n;
+
+            try writer.print("│ {s:<9} │ {s:<4} │ {d:>7.2}ns │ {d:>7.2}ns │ {d:>8.2}x │\n", .{
+                op_name, TNames[tidx], avg_n, avg_q, slowdown,
+            });
+        }
+        if (j != Ops.len - 1) try writer.print("├───────────┼──────┼───────────┼───────────┼───────────┤\n", .{});
+    }
+
+    try writer.print("└───────────┴──────┴───────────┴───────────┴───────────┘\n", .{});
+}
+
+fn bench_crossTypeVsNative(writer: *std.Io.Writer) !void {
+    const ITERS: usize = 100_000;
+    const SAMPLES: usize = 5;
+
+    const getValT = struct {
+        fn f(comptime TT: type, i: usize) TT {
+            // Keep values safe and non-zero to avoid division by zero or overflows during cross-casting
+            const v = (i % 50) + 1;
+            return if (comptime @typeInfo(TT) == .float) @floatFromInt(v) else @intCast(v);
+        }
+    }.f;
+
+    // Helper for the Native baseline: explicitly casting T2 to T1 before the operation
+    const castTo = struct {
+        fn f(comptime DestT: type, comptime SrcT: type, val: SrcT) DestT {
+            if (comptime DestT == SrcT) return val;
+            const src_info = @typeInfo(SrcT);
+            const dest_info = @typeInfo(DestT);
+
+            if (dest_info == .int and src_info == .int) return @intCast(val);
+            if (dest_info == .float and src_info == .int) return @floatFromInt(val);
+            if (dest_info == .int and src_info == .float) return @intFromFloat(val);
+            if (dest_info == .float and src_info == .float) return @floatCast(val);
+            unreachable;
+        }
+    }.f;
+
+    const Types = .{ i16, i64, i128, f32, f64 };
+    const TNames = .{ "i16", "i64", "i128", "f32", "f64" };
+    const Ops = .{ "add", "mulBy", "divBy" };
+
+    try writer.print(
+        \\
+        \\ Cross-Type Overhead Analysis: Scalar vs Native
+        \\
+        \\┌─────────┬──────┬──────┬───────────┬───────────┬───────────┐
+        \\│ Op      │ T1   │ T2   │ Native    │ Scalar    │ Slowdown  │
+        \\├─────────┼──────┼──────┼───────────┼───────────┼───────────┤
+        \\
+    , .{});
+
+    inline for (Ops, 0..) |op_name, j| {
+        inline for (Types, 0..) |T1, t1_idx| {
+            inline for (Types, 0..) |T2, t2_idx| {
+                var native_total_ns: f64 = 0;
+                var quantity_total_ns: f64 = 0;
+
+                const M1 = Scalar(T1, .init(.{ .L = 1 }), .init(.{}));
+                const M2 = Scalar(T2, .init(.{ .L = 1 }), .init(.{}));
+                const S2 = Scalar(T2, .init(.{ .T = 1 }), .init(.{}));
+
+                std.mem.doNotOptimizeAway({
+                    for (0..SAMPLES) |_| {
+                        // --- 1. Benchmark Native (Cast T2 to T1, then math) ---
+                        const n_start = getTime();
+                        for (0..ITERS) |i| {
+                            const a = getValT(T1, i);
+                            const b_raw = getValT(T2, 2);
+                            const b = castTo(T1, T2, b_raw);
+
+                            _ = if (comptime std.mem.eql(u8, op_name, "add"))
+                                a + b
+                            else if (comptime std.mem.eql(u8, op_name, "mulBy"))
+                                a * b
+                            else if (comptime @typeInfo(T1) == .int)
+                                @divTrunc(a, b)
+                            else
+                                a / b;
+                        }
+                        const n_end = getTime();
+                        native_total_ns += @as(f64, @floatFromInt(n_start.durationTo(n_end).toNanoseconds()));
+
+                        // --- 2. Benchmark Scalar ---
+                        const q_start = getTime();
+                        for (0..ITERS) |i| {
+                            const qa = M1{ .value = getValT(T1, i) };
+                            const qb = if (comptime std.mem.eql(u8, op_name, "divBy"))
+                                S2{ .value = getValT(T2, 2) }
+                            else
+                                M2{ .value = getValT(T2, 2) };
+
+                            _ = if (comptime std.mem.eql(u8, op_name, "add"))
+                                qa.add(qb)
+                            else if (comptime std.mem.eql(u8, op_name, "mulBy"))
+                                qa.mulBy(qb)
+                            else
+                                qa.divBy(qb);
+                        }
+                        const q_end = getTime();
+                        quantity_total_ns += @as(f64, @floatFromInt(q_start.durationTo(q_end).toNanoseconds()));
+                    }
+
+                    const avg_n = (native_total_ns / SAMPLES) / @as(f64, @floatFromInt(ITERS));
+                    const avg_q = (quantity_total_ns / SAMPLES) / @as(f64, @floatFromInt(ITERS));
+                    const slowdown = avg_q / avg_n;
+
+                    try writer.print("│ {s:<7} │ {s:<4} │ {s:<4} │ {d:>7.2}ns │ {d:>7.2}ns │ {d:>8.2}x │\n", .{
+                        op_name, TNames[t1_idx], TNames[t2_idx], avg_n, avg_q, slowdown,
+                    });
+                });
+            }
+        }
+        if (j != Ops.len - 1) {
+            try writer.print("├─────────┼──────┼──────┼───────────┼───────────┼───────────┤\n", .{});
+        }
+    }
+
+    try writer.print("└─────────┴──────┴──────┴───────────┴───────────┴───────────┘\n", .{});
+}
+
+fn bench_Vector(writer: *std.Io.Writer) !void {
+    const ITERS: usize = 10_000;
+    const SAMPLES: usize = 10;
+
+    const getVal = struct {
+        fn f(comptime TT: type, i: usize, comptime mask: u7) TT {
+            const v: u8 = @as(u8, @truncate(i & @as(usize, mask))) + 1;
+            return if (comptime @typeInfo(TT) == .float) @floatFromInt(v) else @intCast(v);
+        }
+    }.f;
+
+    const computeStats = struct {
+        fn f(samples: []f64, iters: usize) f64 {
+            std.mem.sort(f64, samples, {}, std.sort.asc(f64));
+            const mid = samples.len / 2;
+            const median_ns = if (samples.len % 2 == 0)
+                (samples[mid - 1] + samples[mid]) / 2.0
+            else
+                samples[mid];
+            return median_ns / @as(f64, @floatFromInt(iters));
+        }
+    }.f;
+
+    try writer.print(
+        \\
+        \\ Vector<N, T> benchmark — {d} iterations, {d} samples/cell
+        \\ (Results in ns/op)
+        \\
+        \\┌─────────────┬──────┬─────────┬─────────┬─────────┐
+        \\│ Operation   │ Type │   Len=3 │   Len=4 │  Len=16 │
+        \\├─────────────┼──────┼─────────┼─────────┼─────────┤
+        \\
+    , .{ ITERS, SAMPLES });
+
+    const Types = .{ i32, i64, i128, f32, f64 };
+    const TNames = .{ "i32", "i64", "i128", "f32", "f64" };
+    const Lengths = .{ 3, 4, 16 };
+    const Ops = .{ "add", "divBy", "mulByScalar", "length" };
+
+    inline for (Ops, 0..) |op_name, o_idx| {
+        inline for (Types, TNames) |T, tname| {
+            try writer.print("│ {s:<11} │ {s:<4} │", .{ op_name, tname });
+
+            inline for (Lengths) |len| {
+                const Q_base = Scalar(T, .init(.{ .L = 1 }), .init(.{}));
+                const Q_time = Scalar(T, .init(.{ .T = 1 }), .init(.{}));
+                const V = Vector(len, Q_base);
+
+                var samples: [SAMPLES]f64 = undefined;
+
+                std.mem.doNotOptimizeAway({
+                    for (0..SAMPLES) |s_idx| {
+                        const t_start = getTime();
+                        for (0..ITERS) |i| {
+                            const v1 = V.initDefault(getVal(T, i, 63));
+
+                            if (comptime std.mem.eql(u8, op_name, "add")) {
+                                const v2 = V.initDefault(getVal(T, i +% 7, 63));
+                                _ = v1.add(v2);
+                            } else if (comptime std.mem.eql(u8, op_name, "divBy")) {
+                                _ = v1.divBy(V.initDefault(getVal(T, i +% 2, 63)));
+                            } else if (comptime std.mem.eql(u8, op_name, "mulByScalar")) {
+                                const s_val = Q_time{ .value = getVal(T, i +% 2, 63) };
+                                _ = v1.mulByScalar(s_val);
+                            } else if (comptime std.mem.eql(u8, op_name, "length")) {
+                                _ = v1.length();
+                            }
+                        }
+                        const t_end = getTime();
+
+                        samples[s_idx] = @as(f64, @floatFromInt(t_start.durationTo(t_end).toNanoseconds()));
+                    }
+
+                    const median_ns_per_op = computeStats(&samples, ITERS);
+                    try writer.print(" {d:>7.1} │", .{median_ns_per_op});
+                });
+            }
+            try writer.print("\n", .{});
+        }
+
+        if (o_idx < Ops.len - 1) {
+            try writer.print("├─────────────┼──────┼─────────┼─────────┼─────────┤\n", .{});
+        }
+    }
+    try writer.print("└─────────────┴──────┴─────────┴─────────┴─────────┘\n", .{});
+}

src/main.zig

@@ -1,826 +1,16 @@
 const std = @import("std");
-const hlp = @import("helper.zig");
 
-const Scales = @import("Scales.zig");
+pub const Scalar = @import("Scalar.zig").Scalar;
-const UnitScale = Scales.UnitScale;
+pub const Vector = @import("Vector.zig").Vector;
-const Dimensions = @import("Dimensions.zig");
+pub const Dimensions = @import("Dimensions.zig");
-const Dimension = Dimensions.Dimension;
+pub const Scales = @import("Scales.zig");
+pub const Base = @import("Base.zig");
 
-pub fn Quantity(T: type, d: Dimensions, s: Scales) type {
+test {
-    return struct {
+    _ = @import("Scalar.zig");
-        value: T,
+    _ = @import("Vector.zig");
-
+    _ = @import("Dimensions.zig");
-        const Self = @This();
+    _ = @import("Scales.zig");
-        pub const Vec3: type = QuantityVec3(Self);
+    _ = @import("Base.zig");
-        pub const ValueType: type = T;
+    _ = @import("helper.zig");
-
-        pub const dims: Dimensions = d;
-        pub const scales = s;
-
-        /// Internal helper to convert any supported T to f64 for math
-        fn toF64(val: anytype) f64 {
-            const TIn = @TypeOf(val);
-            return switch (@typeInfo(TIn)) {
-                .int => @floatFromInt(val),
-                .float => @floatCast(val),
-                else => @compileError("Unsupported type for Quantity"),
-            };
-        }
-
-        /// Internal helper to convert f64 back to the target T
-        fn fromF64(val: f64) T {
-            return switch (@typeInfo(T)) {
-                .int => @intFromFloat(@round(val)),
-                .float => @floatCast(val),
-                else => unreachable,
-            };
-        }
-
-        /// Helper for integer power of 10 at comptime
-        fn pow10(comptime exp: i32) T {
-            var res: T = 1;
-            var i: i32 = 0;
-            const abs_exp = if (exp < 0) -exp else exp;
-            while (i < abs_exp) : (i += 1) res *= 10;
-            return res;
-        }
-
-        pub fn add(self: Self, rhs: anytype) Quantity(
-            T,
-            dims,
-            scales.min(@TypeOf(rhs).scales),
-        ) {
-            if (comptime !dims.eql(@TypeOf(rhs).dims))
-                @compileError("Dimension mismatch in add");
-
-            const TargetType = Quantity(T, dims, scales.min(@TypeOf(rhs).scales));
-            const lhs_converted = self.to(TargetType);
-            const rhs_converted = rhs.to(TargetType);
-
-            return .{ .value = lhs_converted.value + rhs_converted.value };
-        }
-
-        pub fn sub(self: Self, rhs: anytype) Quantity(
-            T,
-            dims,
-            scales.min(@TypeOf(rhs).scales),
-        ) {
-            if (comptime !dims.eql(@TypeOf(rhs).dims))
-                @compileError("Dimension mismatch in sub");
-
-            const TargetType = Quantity(T, dims, scales.min(@TypeOf(rhs).scales));
-            const lhs_converted = self.to(TargetType);
-            const rhs_converted = rhs.to(TargetType);
-
-            return .{ .value = lhs_converted.value - rhs_converted.value };
-        }
-
-        pub fn mulBy(self: Self, rhs: anytype) Quantity(
-            T,
-            dims.add(@TypeOf(rhs).dims),
-            scales.min(@TypeOf(rhs).scales),
-        ) {
-            const self_ = self.to(Quantity(T, dims, scales.min(@TypeOf(rhs).scales)));
-            const rhs_ = rhs.to(Quantity(T, @TypeOf(rhs).dims, scales.min(@TypeOf(rhs).scales)));
-            return .{ .value = self_.value * rhs_.value };
-        }
-
-        pub fn divBy(self: Self, rhs: anytype) Quantity(
-            T,
-            dims.sub(@TypeOf(rhs).dims),
-            scales.min(@TypeOf(rhs).scales),
-        ) {
-            const self_ = self.to(Quantity(T, dims, scales.min(@TypeOf(rhs).scales)));
-            const rhs_ = rhs.to(Quantity(T, @TypeOf(rhs).dims, scales.min(@TypeOf(rhs).scales)));
-            return .{ .value = fromF64((toF64(self_.value) / toF64(rhs_.value))) };
-        }
-
-        pub fn scale(self: Self, sc: T) Self {
-            return .{ .value = self.value * sc };
-        }
-
-        pub fn to(self: Self, comptime Dest: type) Dest {
-            if (comptime !dims.eql(Dest.dims))
-                @compileError("Dimension mismatch: " ++ dims.str() ++ " vs " ++ Dest.dims.str());
-            if (comptime @TypeOf(self) == Dest)
-                return self;
-
-            const source_factor = scales.getFactor(dims);
-            const dest_factor = Dest.scales.getFactor(Dest.dims);
-            const ratio = source_factor / dest_factor;
-            const result_f = toF64(self.value) * ratio;
-
-            const DestT = Dest.ValueType;
-            return .{ .value = switch (@typeInfo(DestT)) {
-                .int => @intFromFloat(@round(result_f)),
-                .float => @floatCast(result_f),
-                else => unreachable,
-            } };
-        }
-
-        pub fn vec3(self: Self) Vec3 {
-            return .{ .x = self.value, .y = self.value, .z = self.value };
-        }
-
-        pub fn format(
-            self: Self,
-            writer: *std.Io.Writer,
-        ) !void {
-            try writer.print("{d}", .{self.value});
-            var iter = std.EnumSet(Dimension).initFull().iterator();
-            var first = true;
-            while (iter.next()) |bu| {
-                const v = dims.get(bu);
-                if (v == 0) continue;
-                if (!first)
-                    try writer.writeAll(".");
-
-                first = false;
-
-                const uscale = scales.get(bu);
-                if (bu == .T and (uscale == .min or uscale == .hour or uscale == .year))
-                    try writer.print("{s}", .{uscale.str()})
-                else
-                    try writer.print("{s}{s}", .{ uscale.str(), bu.unit() });
-
-                if (v != 1)
-                    try hlp.printSuperscript(writer, v);
-            }
-        }
-    };
-}
-
-pub fn QuantityVec3(Q: type) type {
-    const T = Q.ValueType;
-    const d: Dimensions = Q.dims;
-    const s: Scales = Q.scales;
-
-    return struct {
-        x: T,
-        y: T,
-        z: T,
-
-        const Self = @This();
-        pub const QuantityType = Q;
-        pub const ValueType = T;
-        pub const dims: Dimensions = d;
-        pub const scales = s;
-
-        pub const zero = Self{ .x = 0, .y = 0, .z = 0 };
-        pub const one = Self{ .x = 1, .y = 1, .z = 1 };
-
-        pub fn initDefault(v: T) Self {
-            return .{ .x = v, .y = v, .z = v };
-        }
-
-        pub fn add(self: Self, rhs: anytype) QuantityVec3(Quantity(T, d, s.min(@TypeOf(rhs).scales))) {
-            const Tr = @TypeOf(rhs);
-            // We leverage the logic in the scalar Quantity.add
-            const qx = (Q{ .value = self.x }).add(Tr.QuantityType{ .value = rhs.x });
-            const qy = (Q{ .value = self.y }).add(Tr.QuantityType{ .value = rhs.y });
-            const qz = (Q{ .value = self.z }).add(Tr.QuantityType{ .value = rhs.z });
-
-            return .{
-                .x = qx.value,
-                .y = qy.value,
-                .z = qz.value,
-            };
-        }
-
-        pub fn sub(self: Self, rhs: anytype) QuantityVec3(Quantity(T, d, s.min(@TypeOf(rhs).scales))) {
-            const Tr = @TypeOf(rhs);
-            const qx = (Q{ .value = self.x }).sub(Tr.QuantityType{ .value = rhs.x });
-            const qy = (Q{ .value = self.y }).sub(Tr.QuantityType{ .value = rhs.y });
-            const qz = (Q{ .value = self.z }).sub(Tr.QuantityType{ .value = rhs.z });
-
-            return .{
-                .x = qx.value,
-                .y = qy.value,
-                .z = qz.value,
-            };
-        }
-
-        pub fn divBy(
-            self: Self,
-            rhs: anytype,
-        ) QuantityVec3(Quantity(T, d.sub(@TypeOf(rhs).dims), s.min(@TypeOf(rhs).scales))) {
-            const Tr = @TypeOf(rhs);
-            return .{
-                .x = (Q{ .value = self.x }).divBy(Tr.QuantityType{ .value = rhs.x }).value,
-                .y = (Q{ .value = self.y }).divBy(Tr.QuantityType{ .value = rhs.y }).value,
-                .z = (Q{ .value = self.z }).divBy(Tr.QuantityType{ .value = rhs.z }).value,
-            };
-        }
-
-        pub fn mulBy(
-            self: Self,
-            rhs: anytype,
-        ) QuantityVec3(Quantity(T, d.sub(@TypeOf(rhs).dims), s.min(@TypeOf(rhs).scales))) {
-            const Tr = @TypeOf(rhs);
-            return .{
-                .x = (Q{ .value = self.x }).mulBy(Tr.QuantityType{ .value = rhs.x }).value,
-                .y = (Q{ .value = self.y }).mulBy(Tr.QuantityType{ .value = rhs.y }).value,
-                .z = (Q{ .value = self.z }).mulBy(Tr.QuantityType{ .value = rhs.z }).value,
-            };
-        }
-
-        pub fn divByScalar(
-            self: Self,
-            scalar: anytype,
-        ) QuantityVec3(Quantity(T, d.sub(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) {
-            const q_x = Q{ .value = self.x };
-            const q_y = Q{ .value = self.y };
-            const q_z = Q{ .value = self.z };
-
-            return .{
-                .x = q_x.divBy(scalar).value,
-                .y = q_y.divBy(scalar).value,
-                .z = q_z.divBy(scalar).value,
-            };
-        }
-
-        pub fn mulByScalar(
-            self: Self,
-            scalar: anytype,
-        ) QuantityVec3(Quantity(T, d.add(@TypeOf(scalar).dims), s.min(@TypeOf(scalar).scales))) {
-            const q_x = Q{ .value = self.x };
-            const q_y = Q{ .value = self.y };
-            const q_z = Q{ .value = self.z };
-
-            return .{
-                .x = q_x.mulBy(scalar).value,
-                .y = q_y.mulBy(scalar).value,
-                .z = q_z.mulBy(scalar).value,
-            };
-        }
-
-        pub fn negate(self: Self) Self {
-            return .{ .x = -self.x, .y = -self.y, .z = -self.z };
-        }
-
-        pub fn scale(self: Self, rhs: T) Self {
-            return .{
-                .x = (Q{ .value = self.x }).scale(rhs).value,
-                .y = (Q{ .value = self.y }).scale(rhs).value,
-                .z = (Q{ .value = self.z }).scale(rhs).value,
-            };
-        }
-
-        pub fn to(self: Self, comptime DestQ: type) QuantityVec3(DestQ) {
-            return .{
-                .x = (Q{ .value = self.x }).to(DestQ).value,
-                .y = (Q{ .value = self.y }).to(DestQ).value,
-                .z = (Q{ .value = self.z }).to(DestQ).value,
-            };
-        }
-
-        pub fn format(self: Self, writer: *std.Io.Writer) !void {
-            try writer.print("({d:.2}, {d:.2}, {d:.2})", .{ self.x, self.y, self.z });
-            var iter = std.EnumSet(Dimension).initFull().iterator();
-            var first = true;
-            while (iter.next()) |bu| {
-                const v = dims.get(bu);
-                if (v == 0) continue;
-                if (!first) try writer.writeAll(".");
-                first = false;
-                try writer.print("{s}{s}", .{ scales.get(bu).str(), bu.unit() });
-                if (v != 1) try hlp.printSuperscript(writer, v);
-            }
-        }
-
-        pub fn lengthSqr(self: Self) T {
-            return self.x * self.x + self.y * self.y + self.z * self.z;
-        }
-
-        pub fn length(self: Self) T {
-            if (comptime hlp.isInt(T))
-                return self.isqrt()
-            else
-                return @sqrt(self.x * self.x + self.y * self.y + self.z * self.z);
-        }
-
-        fn isqrt(self: Self) T {
-            const squared_sum = (self.x * self.x) + (self.y * self.y) + (self.z * self.z);
-            if (squared_sum <= 0) return 0;
-
-            var x = squared_sum;
-            var y = @divTrunc(x + 1, 2);
-            while (y < x) {
-                x = y;
-                y = @divTrunc(x + @divTrunc(squared_sum, x), 2);
-            }
-            return x;
-        }
-    };
-}
-
-pub fn main(_: std.process.Init) void {}
-
-test "Generate quantity" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = -3 }));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .n }));
-
-    const distance = Meter{ .value = 10 };
-    const time = Second{ .value = 2 };
-
-    try std.testing.expectEqual(10, distance.value);
-    try std.testing.expectEqual(2, time.value);
-}
-
-test "Add" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-
-    const distance = Meter{ .value = 10 };
-    const distance2 = Meter{ .value = 20 };
-
-    const added = distance.add(distance2);
-    try std.testing.expectEqual(30, added.value);
-    try std.testing.expectEqual(1, @TypeOf(added).dims.get(.L));
-    std.debug.print("KiloMeter {f} + {f} = {f} OK\n", .{ distance, distance2, added });
-
-    const KiloMeter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const distance3 = KiloMeter{ .value = 2 };
-    const added2 = distance.add(distance3);
-    try std.testing.expectEqual(2010, added2.value);
-    try std.testing.expectEqual(1, @TypeOf(added2).dims.get(.L));
-    std.debug.print("KiloMeter {f} + {f} = {f} OK\n", .{ distance, distance3, added2 });
-
-    const added3 = distance3.add(distance).to(KiloMeter);
-    try std.testing.expectEqual(2, added3.value);
-    try std.testing.expectEqual(1, @TypeOf(added3).dims.get(.L));
-    std.debug.print("KiloMeter {f} + {f} = {f} OK\n", .{ distance3, distance, added3 });
-
-    const KiloMeter_f = Quantity(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const distance4 = KiloMeter_f{ .value = 2 };
-    const added4 = distance4.add(distance).to(KiloMeter_f);
-    try std.testing.expectApproxEqAbs(2.01, added4.value, 0.000001);
-    try std.testing.expectEqual(1, @TypeOf(added4).dims.get(.L));
-    std.debug.print("KiloMeter_f {f} + {f} = {f} OK\n", .{ distance4, distance, added4 });
-}
-
-test "Sub" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const KiloMeter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const KiloMeter_f = Quantity(f64, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-
-    const a = Meter{ .value = 500 };
-    const b = Meter{ .value = 200 };
-    const diff = a.sub(b);
-    try std.testing.expectEqual(300, diff.value);
-    std.debug.print("Sub: {f} - {f} = {f} OK\n", .{ a, b, diff });
-
-    const km = KiloMeter{ .value = 1 };
-    const diff2 = a.sub(km);
-    std.debug.print("Sub cross-scale: {f} - {f} = {f}\n", .{ a, km, diff2 });
-
-    const km_f = KiloMeter_f{ .value = 2.5 };
-    const m_f = Meter{ .value = 500 };
-    const diff3 = km_f.sub(m_f);
-    try std.testing.expectApproxEqAbs(2000, diff3.value, 1e-4);
-    std.debug.print("Sub float cross-scale: {f} - {f} = {f} OK\n", .{ km_f, m_f, diff3 });
-}
-
-test "MulBy" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const d = Meter{ .value = 3.0 };
-    const t = Second{ .value = 4.0 };
-
-    const area_time = d.mulBy(t);
-    try std.testing.expectEqual(12, area_time.value);
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
-    std.debug.print("MulBy: {f} * {f} = {f} OK\n", .{ d, t, area_time });
-
-    const d2 = Meter{ .value = 5.0 };
-    const area = d.mulBy(d2);
-    try std.testing.expectEqual(15, area.value);
-    try std.testing.expectEqual(2, @TypeOf(area).dims.get(.L));
-    try std.testing.expectEqual(0, @TypeOf(area).dims.get(.T));
-    std.debug.print("MulBy: {f} * {f} = {f} OK\n", .{ d, d2, area });
-}
-
-test "MulBy with scale" {
-    const KiloMeter = Quantity(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const KiloGram = Quantity(f32, Dimensions.init(.{ .M = 1 }), Scales.init(.{ .M = .k }));
-
-    const dist = KiloMeter{ .value = 2.0 };
-    const mass = KiloGram{ .value = 3.0 };
-    const prod = dist.mulBy(mass);
-    try std.testing.expectEqual(1, @TypeOf(prod).dims.get(.L));
-    try std.testing.expectEqual(1, @TypeOf(prod).dims.get(.M));
-    std.debug.print("MulBy scaled: {f} * {f} = {f} OK\n", .{ dist, mass, prod });
-}
-
-test "MulBy with type change" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-    const KmSec = Quantity(f32, Dimensions.init(.{ .L = 1, .T = 1 }), Scales.init(.{ .L = .k }));
-
-    const d = Meter{ .value = 3.0 };
-    const t = Second{ .value = 4.0 };
-
-    const area_time = d.mulBy(t).to(KmSec);
-    try std.testing.expectEqual(12, area_time.value);
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
-    std.debug.print("MulBy: {f} * {f} = {f} OK\n", .{ d, t, area_time });
-}
-
-test "MulBy small" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .n }));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const d = Meter{ .value = 3.0 };
-    const t = Second{ .value = 4.0 };
-
-    const area_time = d.mulBy(t);
-    try std.testing.expectEqual(12, area_time.value);
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.L));
-    try std.testing.expectEqual(1, @TypeOf(area_time).dims.get(.T));
-    std.debug.print("MulBy: {f} * {f} = {f} OK\n", .{ d, t, area_time });
-}
-
-test "Scale" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const d = Meter{ .value = 7 };
-    const scaled = d.scale(3);
-    try std.testing.expectEqual(21, scaled.value);
-    try std.testing.expectEqual(1, @TypeOf(scaled).dims.get(.L));
-    std.debug.print("Scale int: {f} * 3 = {f} OK\n", .{ d, scaled });
-
-    const t = Second{ .value = 1.5 };
-    const scaled_f = t.scale(4.0);
-    try std.testing.expectApproxEqAbs(@as(f32, 6.0), scaled_f.value, 1e-4);
-    std.debug.print("Scale float: {f} * 4 = {f} OK\n", .{ t, scaled_f });
-}
-
-test "Chained: velocity and acceleration" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const dist = Meter{ .value = 100.0 };
-    const t1 = Second{ .value = 5.0 };
-    const velocity = dist.divBy(t1);
-    try std.testing.expectEqual(20, velocity.value);
-    try std.testing.expectEqual(1, @TypeOf(velocity).dims.get(.L));
-    try std.testing.expectEqual(-1, @TypeOf(velocity).dims.get(.T));
-
-    const t2 = Second{ .value = 4.0 };
-    const accel = velocity.divBy(t2);
-    try std.testing.expectEqual(5, accel.value);
-    try std.testing.expectEqual(1, @TypeOf(accel).dims.get(.L));
-    try std.testing.expectEqual(-2, @TypeOf(accel).dims.get(.T));
-
-    std.debug.print("Velocity: {f}, Acceleration: {f} OK\n", .{ velocity, accel });
-}
-
-test "DivBy integer exact" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Quantity(f32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const dist = Meter{ .value = 120 };
-    const time = Second{ .value = 4 };
-    const vel = dist.divBy(time);
-
-    try std.testing.expectEqual(30, vel.value);
-    try std.testing.expectEqual(1, @TypeOf(vel).dims.get(.L));
-    try std.testing.expectEqual(-1, @TypeOf(vel).dims.get(.T));
-    std.debug.print("DivBy int: {f} / {f} = {f} OK\n", .{ dist, time, vel });
-}
-
-test "Conversion chain: km -> m -> cm" {
-    const KiloMeter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const CentiMeter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .c }));
-
-    const km = KiloMeter{ .value = 15 };
-    const m = km.to(Meter);
-    const cm = m.to(CentiMeter);
-
-    try std.testing.expectEqual(15_000, m.value);
-    try std.testing.expectEqual(1_500_000, cm.value);
-    std.debug.print("Chain: {f} -> {f} -> {f} OK\n", .{ km, m, cm });
-}
-
-test "Conversion: hours -> minutes -> seconds" {
-    const Hour = Quantity(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .hour }));
-    const Minute = Quantity(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{ .T = .min }));
-    const Second = Quantity(i128, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-    const h = Hour{ .value = 1.0 };
-    const min = h.to(Minute);
-    const sec = min.to(Second);
-
-    try std.testing.expectEqual(60, min.value);
-    try std.testing.expectEqual(3600, sec.value);
-    std.debug.print("Time chain: {f} -> {f} -> {f} OK\n", .{ h, min, sec });
-}
-
-test "Negative values" {
-    const Meter = Quantity(i128, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-
-    const a = Meter{ .value = 5 };
-    const b = Meter{ .value = 20 };
-    const diff = a.sub(b);
-    try std.testing.expectEqual(-15, diff.value);
-    std.debug.print("Negative sub: {f} - {f} = {f} OK\n", .{ a, b, diff });
-}
-
-test "Format Quantity" {
-    const MeterPerSecondSq = Quantity(
-        f32,
-        Dimensions.init(.{ .L = 1, .T = -2 }),
-        Scales.init(.{ .T = .n }),
-    );
-    const KgMeterPerSecond = Quantity(
-        f32,
-        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
-        Scales.init(.{ .M = .k }),
-    );
-
-    const accel = MeterPerSecondSq{ .value = 9.81 };
-    const momentum = KgMeterPerSecond{ .value = 42.0 };
-
-    std.debug.print("Acceleration: {f}\n", .{accel});
-    std.debug.print("Momentum: {f}\n", .{momentum});
-}
-
-test "Format Vector3" {
-    const MeterPerSecondSq = Quantity(
-        f32,
-        Dimensions.init(.{ .L = 1, .T = -2 }),
-        Scales.init(.{ .T = .n }),
-    );
-    const KgMeterPerSecond = Quantity(
-        f32,
-        Dimensions.init(.{ .M = 1, .L = 1, .T = -1 }),
-        Scales.init(.{ .M = .k }),
-    );
-
-    const accel = MeterPerSecondSq.Vec3.initDefault(9.81);
-    const momentum = KgMeterPerSecond.Vec3{ .x = 43, .y = 0, .z = 11 };
-
-    std.debug.print("Acceleration: {f}\n", .{accel});
-    std.debug.print("Momentum: {f}\n", .{momentum});
-}
-
-test "Vec3 Init and Basic Arithmetic" {
-    const Meter = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Vec3M = Meter.Vec3;
-
-    // Test zero, one, initDefault
-    const v_zero = Vec3M.zero;
-    try std.testing.expectEqual(0, v_zero.x);
-
-    const v_one = Vec3M.one;
-    try std.testing.expectEqual(1, v_one.x);
-
-    const v_def = Vec3M.initDefault(5);
-    try std.testing.expectEqual(5, v_def.x);
-    try std.testing.expectEqual(5, v_def.y);
-    try std.testing.expectEqual(5, v_def.z);
-
-    // Test add and sub
-    const v1 = Vec3M{ .x = 10, .y = 20, .z = 30 };
-    const v2 = Vec3M{ .x = 2, .y = 4, .z = 6 };
-
-    const added = v1.add(v2);
-    try std.testing.expectEqual(12, added.x);
-    try std.testing.expectEqual(24, added.y);
-    try std.testing.expectEqual(36, added.z);
-
-    const subbed = v1.sub(v2);
-    try std.testing.expectEqual(8, subbed.x);
-    try std.testing.expectEqual(16, subbed.y);
-    try std.testing.expectEqual(24, subbed.z);
-
-    // Test negate
-    const neg = v1.negate();
-    try std.testing.expectEqual(-10, neg.x);
-    try std.testing.expectEqual(-20, neg.y);
-    try std.testing.expectEqual(-30, neg.z);
-}
-
-test "Vec3 Kinematics (Scalar Mul/Div)" {
-    const Meter = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Second = Quantity(i32, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-    const Vec3M = Meter.Vec3;
-
-    const pos = Vec3M{ .x = 100, .y = 200, .z = 300 };
-    const time = Second{ .value = 10 };
-
-    // Vector divided by scalar Quantity (Velocity = Position / Time)
-    const vel = pos.divByScalar(time);
-    try std.testing.expectEqual(10, vel.x);
-    try std.testing.expectEqual(20, vel.y);
-    try std.testing.expectEqual(30, vel.z);
-    try std.testing.expectEqual(1, @TypeOf(vel).dims.get(.L));
-    try std.testing.expectEqual(-1, @TypeOf(vel).dims.get(.T));
-
-    // Vector multiplied by scalar Quantity (Position = Velocity * Time)
-    const new_pos = vel.mulByScalar(time);
-    try std.testing.expectEqual(100, new_pos.x);
-    try std.testing.expectEqual(200, new_pos.y);
-    try std.testing.expectEqual(300, new_pos.z);
-    try std.testing.expectEqual(1, @TypeOf(new_pos).dims.get(.L));
-    try std.testing.expectEqual(0, @TypeOf(new_pos).dims.get(.T));
-}
-
-test "Vec3 Element-wise Math and Scaling" {
-    const Meter = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const Vec3M = Meter.Vec3;
-
-    const v1 = Vec3M{ .x = 10, .y = 20, .z = 30 };
-    const v2 = Vec3M{ .x = 2, .y = 5, .z = 10 };
-
-    // Element-wise division
-    const div = v1.divBy(v2);
-    try std.testing.expectEqual(5, div.x);
-    try std.testing.expectEqual(4, div.y);
-    try std.testing.expectEqual(3, div.z);
-    try std.testing.expectEqual(0, @TypeOf(div).dims.get(.L)); // M / M = Dimensionless
-
-    // Scale by primitive
-    const scaled = v1.scale(2);
-    try std.testing.expectEqual(20, scaled.x);
-    try std.testing.expectEqual(40, scaled.y);
-    try std.testing.expectEqual(60, scaled.z);
-}
-
-test "Vec3 Conversions" {
-    const KiloMeter = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-    const Meter = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-
-    const v_km = KiloMeter.Vec3{ .x = 1, .y = 2, .z = 3 };
-    const v_m = v_km.to(Meter);
-
-    try std.testing.expectEqual(1000, v_m.x);
-    try std.testing.expectEqual(2000, v_m.y);
-    try std.testing.expectEqual(3000, v_m.z);
-
-    // Type checking the result
-    try std.testing.expectEqual(1, @TypeOf(v_m).dims.get(.L));
-    try std.testing.expectEqual(UnitScale.none, @TypeOf(v_m).scales.get(.L));
-}
-
-test "Vec3 Length" {
-    const MeterInt = Quantity(i32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-    const MeterFloat = Quantity(f32, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-
-    // Integer length (using your custom isqrt)
-    // 3-4-5 triangle on XY plane
-    const v_int = MeterInt.Vec3{ .x = 3, .y = 4, .z = 0 };
-    try std.testing.expectEqual(25, v_int.lengthSqr());
-    try std.testing.expectEqual(5, v_int.length());
-
-    // Float length
-    const v_float = MeterFloat.Vec3{ .x = 3.0, .y = 4.0, .z = 0.0 };
-    try std.testing.expectApproxEqAbs(@as(f32, 25.0), v_float.lengthSqr(), 1e-4);
-    try std.testing.expectApproxEqAbs(@as(f32, 5.0), v_float.length(), 1e-4);
-}
-
-test "Comprehensive Benchmark: All Ops × All Types" {
-    const Io = std.Io;
-    const ITERS: usize = 100_000;
-    const SAMPLES: usize = 10; // Number of samples for stats
-
-    var gsink: f64 = 0;
-    const io = std.testing.io;
-
-    // Standard Zig 0.16 timestamp retrieval
-    const getTime = struct {
-        fn f(i: Io) Io.Timestamp {
-            return Io.Clock.awake.now(i);
-        }
-    }.f;
-
-    const fold = struct {
-        fn f(comptime TT: type, s: *f64, v: TT) void {
-            s.* += if (comptime @typeInfo(TT) == .float)
-                @as(f64, @floatCast(v))
-            else
-                @as(f64, @floatFromInt(v));
-        }
-    }.f;
-
-    const getVal = struct {
-        fn f(comptime TT: type, i: usize, comptime mask: u7) TT {
-            const v: u8 = @as(u8, @truncate(i & @as(usize, mask))) + 1;
-            return if (comptime @typeInfo(TT) == .float) @floatFromInt(v) else @intCast(v);
-        }
-    }.f;
-
-    const Stats = struct {
-        median: f64,
-        delta: f64,
-        ops_per_sec: f64,
-    };
-
-    const computeStats = struct {
-        fn f(samples: []f64, iters: usize) Stats {
-            std.mem.sort(f64, samples, {}, std.sort.asc(f64));
-            const mid = samples.len / 2;
-            const median_ns = if (samples.len % 2 == 0) (samples[mid - 1] + samples[mid]) / 2.0 else samples[mid];
-
-            const low = samples[0];
-            const high = samples[samples.len - 1];
-            const delta_ns = (high - low) / 2.0;
-
-            const ns_per_op = median_ns / @as(f64, @floatFromInt(iters));
-            return .{
-                .median = ns_per_op,
-                .delta = (delta_ns / @as(f64, @floatFromInt(iters))),
-                .ops_per_sec = 1_000_000_000.0 / ns_per_op,
-            };
-        }
-    }.f;
-
-    std.debug.print(
-        \\
-        \\ Quantity<T> benchmark — {d} iterations, {d} samples/cell
-        \\
-        \\┌───────────────────┬──────┬─────────────────────┬─────────────────────┐
-        \\│ Operation         │ Type │ ns / op (± delta)   │ Throughput (ops/s)  │
-        \\├───────────────────┼──────┼─────────────────────┼─────────────────────┤
-        \\
-    , .{ ITERS, SAMPLES });
-
-    const Types = .{ i16, i32, i64, i128, i256, f32, f64, f128 };
-    const TNames = .{ "i16", "i32", "i64", "i128", "i256", "f32", "f64", "f128" };
-    const Ops = .{ "add", "sub", "mulBy", "divBy", "scale", "to" };
-
-    var results_matrix: [Ops.len][Types.len]f64 = undefined;
-
-    comptime var tidx: usize = 0;
-    inline for (Types, TNames) |T, tname| {
-        const M = Quantity(T, Dimensions.init(.{ .L = 1 }), Scales.init(.{}));
-        const KM = Quantity(T, Dimensions.init(.{ .L = 1 }), Scales.init(.{ .L = .k }));
-        const S = Quantity(T, Dimensions.init(.{ .T = 1 }), Scales.init(.{}));
-
-        inline for (Ops, 0..) |op_name, oidx| {
-            var samples: [SAMPLES]f64 = undefined;
-
-            for (0..SAMPLES) |s_idx| {
-                var sink: T = 0;
-                const t_start = getTime(io);
-
-                for (0..ITERS) |i| {
-                    const r = if (comptime std.mem.eql(u8, op_name, "add"))
-                        (M{ .value = getVal(T, i, 63) }).add(M{ .value = getVal(T, i +% 7, 63) })
-                    else if (comptime std.mem.eql(u8, op_name, "sub"))
-                        (M{ .value = getVal(T, i +% 10, 63) }).sub(M{ .value = getVal(T, i, 63) })
-                    else if (comptime std.mem.eql(u8, op_name, "mulBy"))
-                        (M{ .value = getVal(T, i, 63) }).mulBy(M{ .value = getVal(T, i +% 1, 63) })
-                    else if (comptime std.mem.eql(u8, op_name, "divBy"))
-                        (M{ .value = getVal(T, i +% 10, 63) }).divBy(S{ .value = getVal(T, i, 63) })
-                    else if (comptime std.mem.eql(u8, op_name, "scale"))
-                        (M{ .value = getVal(T, i, 63) }).scale(getVal(T, i +% 2, 63))
-                    else
-                        (KM{ .value = getVal(T, i, 15) }).to(M);
-
-                    if (comptime @typeInfo(T) == .float) sink += r.value else sink ^= r.value;
-                }
-
-                const t_end = getTime(io);
-                samples[s_idx] = @as(f64, @floatFromInt(t_start.durationTo(t_end).toNanoseconds()));
-                fold(T, &gsink, sink);
-            }
-
-            const stats = computeStats(&samples, ITERS);
-            results_matrix[oidx][tidx] = stats.median;
-
-            std.debug.print("│ {s:<17} │ {s:<4} │ {d:>8.2} ns ±{d:<6.2} │ {d:>19.0} │\n", .{ op_name, tname, stats.median, stats.delta, stats.ops_per_sec });
-        }
-
-        if (comptime tidx < Types.len - 1) {
-            std.debug.print("├───────────────────┼──────┼─────────────────────┼─────────────────────┤\n", .{});
-        }
-        tidx += 1;
-    }
-
-    // Median Summary Table
-    std.debug.print("└───────────────────┴──────┴─────────────────────┴─────────────────────┘\n\n", .{});
-    std.debug.print("Median Summary (ns/op):\n", .{});
-
-    std.debug.print("┌──────────────┬───────┬───────┬───────┬───────┬───────┬───────┬───────┬───────┐\n", .{});
-    std.debug.print("│  Operation   │  i16  │  i32  │  i64  │  i128 │  i256 │  f32  │  f64  │  f128 │\n", .{});
-    std.debug.print("├──────────────┼───────┼───────┼───────┼───────┼───────┼───────┼───────┼───────┤\n", .{});
-
-    inline for (Ops, 0..) |op_name, oidx| {
-        std.debug.print("│  {s:<11} │", .{op_name});
-        var i: usize = 0;
-        while (i < Types.len) : (i += 1) {
-            std.debug.print("{d:>6.1} │", .{results_matrix[oidx][i]});
-        }
-        std.debug.print("\n", .{});
-    }
-
-    std.debug.print("└──────────────┴───────┴───────┴───────┴───────┴───────┴───────┴───────┴───────┘\n", .{});
-
-    std.debug.print("\nAnti-optimisation sink: {d:.4}\n", .{gsink});
-    try std.testing.expect(gsink != 0);
 }