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improve autoHash type switch

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floats shouldn't be autoHash'd as they have multiple representations for some values, preventing it by default is safer
This commit is contained in:
Sahnvour 2020-07-26 22:04:10 +02:00
parent 7ae1b3a6b3
commit 345cb3200c
1 changed files with 9 additions and 11 deletions
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20
lib/std/hash/auto_hash.zig
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@ -81,24 +81,22 @@ pub fn hash(hasher: anytype, key: anytype, comptime strat: HashStrategy) void {
.Undefined,
.Void,
.Null,
.BoundFn,
.ComptimeFloat,
.ComptimeInt,
.Type,
.EnumLiteral,
.Frame,
.Float,
=> @compileError("cannot hash this type"),
// Help the optimizer see that hashing an int is easy by inlining!
// TODO Check if the situation is better after #561 is resolved.
.Int => @call(.{ .modifier = .always_inline }, hasher.update, .{std.mem.asBytes(&key)}),
.Float => |info| hash(hasher, @bitCast(std.meta.Int(false, info.bits), key), strat),
.Bool => hash(hasher, @boolToInt(key), strat),
.Enum => hash(hasher, @enumToInt(key), strat),
.ErrorSet => hash(hasher, @errorToInt(key), strat),
.AnyFrame, .Fn => hash(hasher, @ptrToInt(key), strat),
.AnyFrame, .BoundFn, .Fn => hash(hasher, @ptrToInt(key), strat),
.Pointer => @call(.{ .modifier = .always_inline }, hashPointer, .{ hasher, key, strat }),
@ -266,12 +264,12 @@ test "hash slice deep" {
test "hash struct deep" {
const Foo = struct {
a: u32,
b: f64,
b: u16,
c: *bool,
const Self = @This();
pub fn init(allocator: *mem.Allocator, a_: u32, b_: f64, c_: bool) !Self {
pub fn init(allocator: *mem.Allocator, a_: u32, b_: u16, c_: bool) !Self {
const ptr = try allocator.create(bool);
ptr.* = c_;
return Self{ .a = a_, .b = b_, .c = ptr };
@ -279,9 +277,9 @@ test "hash struct deep" {
};
const allocator = std.testing.allocator;
const foo = try Foo.init(allocator, 123, 1.0, true);
const bar = try Foo.init(allocator, 123, 1.0, true);
const baz = try Foo.init(allocator, 123, 1.0, false);
const foo = try Foo.init(allocator, 123, 10, true);
const bar = try Foo.init(allocator, 123, 10, true);
const baz = try Foo.init(allocator, 123, 10, false);
defer allocator.destroy(foo.c);
defer allocator.destroy(bar.c);
defer allocator.destroy(baz.c);
@ -338,12 +336,12 @@ test "testHash struct" {
test "testHash union" {
const Foo = union(enum) {
A: u32,
B: f32,
B: bool,
C: u32,
};
const a = Foo{ .A = 18 };
var b = Foo{ .B = 12.34 };
var b = Foo{ .B = true };
const c = Foo{ .C = 18 };
testing.expect(testHash(a) == testHash(a));
testing.expect(testHash(a) != testHash(b));