From b729a3f008304d464b431f8ac34ad16cde08ba7b Mon Sep 17 00:00:00 2001
From: expikr <77922942+expikr@users.noreply.github.com>
Date: Sat, 20 Jan 2024 14:32:07 +0800
Subject: [PATCH] std.math: make hypot infer type from argument (#17910)

using peer type resolution
---
 lib/std/math/complex/abs.zig  |  5 ++---
 lib/std/math/complex/sqrt.zig |  8 ++++----
 lib/std/math/hypot.zig        | 22 +++++++++++++++-------
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/lib/std/math/complex/abs.zig b/lib/std/math/complex/abs.zig
index 8716360535..97999ee775 100644
--- a/lib/std/math/complex/abs.zig
+++ b/lib/std/math/complex/abs.zig
@@ -5,9 +5,8 @@ const cmath = math.complex;
 const Complex = cmath.Complex;
 
 /// Returns the absolute value (modulus) of z.
-pub fn abs(z: anytype) @TypeOf(z.re) {
-    const T = @TypeOf(z.re);
-    return math.hypot(T, z.re, z.im);
+pub fn abs(z: anytype) @TypeOf(z.re, z.im) {
+    return math.hypot(z.re, z.im);
 }
 
 const epsilon = 0.0001;
diff --git a/lib/std/math/complex/sqrt.zig b/lib/std/math/complex/sqrt.zig
index fe2880e355..745940b955 100644
--- a/lib/std/math/complex/sqrt.zig
+++ b/lib/std/math/complex/sqrt.zig
@@ -56,13 +56,13 @@ fn sqrt32(z: Complex(f32)) Complex(f32) {
     const dy = @as(f64, y);
 
     if (dx >= 0) {
-        const t = @sqrt((dx + math.hypot(f64, dx, dy)) * 0.5);
+        const t = @sqrt((dx + math.hypot(dx, dy)) * 0.5);
         return Complex(f32).init(
             @as(f32, @floatCast(t)),
             @as(f32, @floatCast(dy / (2.0 * t))),
         );
     } else {
-        const t = @sqrt((-dx + math.hypot(f64, dx, dy)) * 0.5);
+        const t = @sqrt((-dx + math.hypot(dx, dy)) * 0.5);
         return Complex(f32).init(
             @as(f32, @floatCast(@abs(y) / (2.0 * t))),
             @as(f32, @floatCast(math.copysign(t, y))),
@@ -112,10 +112,10 @@ fn sqrt64(z: Complex(f64)) Complex(f64) {
 
     var result: Complex(f64) = undefined;
     if (x >= 0) {
-        const t = @sqrt((x + math.hypot(f64, x, y)) * 0.5);
+        const t = @sqrt((x + math.hypot(x, y)) * 0.5);
         result = Complex(f64).init(t, y / (2.0 * t));
     } else {
-        const t = @sqrt((-x + math.hypot(f64, x, y)) * 0.5);
+        const t = @sqrt((-x + math.hypot(x, y)) * 0.5);
         result = Complex(f64).init(@abs(y) / (2.0 * t), math.copysign(t, y));
     }
 
diff --git a/lib/std/math/hypot.zig b/lib/std/math/hypot.zig
index 9fb569667b..fc5b0ddca8 100644
--- a/lib/std/math/hypot.zig
+++ b/lib/std/math/hypot.zig
@@ -12,11 +12,15 @@ const maxInt = std.math.maxInt;
 /// Returns sqrt(x * x + y * y), avoiding unnecessary overflow and underflow.
 ///
 /// Special Cases:
-///  - hypot(+-inf, y)  = +inf
-///  - hypot(x, +-inf)  = +inf
-///  - hypot(nan, y)    = nan
-///  - hypot(x, nan)    = nan
-pub fn hypot(comptime T: type, x: T, y: T) T {
+///
+/// |   x   |   y   | hypot |
+/// |-------|-------|-------|
+/// | +inf  |  num  | +inf  |
+/// |  num  | +-inf | +inf  |
+/// |  nan  |  any  |  nan  |
+/// |  any  |  nan  |  nan  |
+pub fn hypot(x: anytype, y: anytype) @TypeOf(x, y) {
+    const T = @TypeOf(x, y);
     return switch (T) {
         f32 => hypot32(x, y),
         f64 => hypot64(x, y),
@@ -121,8 +125,12 @@ fn hypot64(x: f64, y: f64) f64 {
 }
 
 test "math.hypot" {
-    try expect(hypot(f32, 0.0, -1.2) == hypot32(0.0, -1.2));
-    try expect(hypot(f64, 0.0, -1.2) == hypot64(0.0, -1.2));
+    const x32: f32 = 0.0;
+    const y32: f32 = -1.2;
+    const x64: f64 = 0.0;
+    const y64: f64 = -1.2;
+    try expect(hypot(x32, y32) == hypot32(0.0, -1.2));
+    try expect(hypot(x64, y64) == hypot64(0.0, -1.2));
 }
 
 test "math.hypot32" {