Commit a3342cea188e1c006b20dd2e4712398f9e8c7fdd | zig

author	Andrew Kelley <andrew@ziglang.org> 2024-11-22 15:10:34-08:00
committer	Andrew Kelley <andrew@ziglang.org> 2024-11-22 15:10:51-08:00
log	a3342cea188e1c006b20dd2e4712398f9e8c7fdd
tree	49450a37ecbe9df4bbe0da4ba471425358e31dc2
parent	73dcd1914071984c5a2e7c195212404824dbfb9e

std.mem.eql: make comparisons for zero-sized and non-sized types work

The `if (@sizeOf(T) == 0) return true;` check simply doesn't work for a number
of cases so that is removed and changed into `@sizeOf(T) != 0` and then
used in the `eqlBytes` check chain to make comparing `enum{}`s possible.

The rest special-cases for comptime-only types and undefined to make
those comparisons possible as well.

Fixes #19929

1 files changed, 32 insertions(+), 1 deletions(-)

lib
- std
  - mem.zig

lib/std/mem.zig+32-1

...	@@ -656,7 +656,18 @@ const eqlBytes_allowed = switch (builtin.zig_backend) {	...	@@ -656,7 +656,18 @@ const eqlBytes_allowed = switch (builtin.zig_backend) {
656		656
657	/// Compares two slices and returns whether they are equal.	657	/// Compares two slices and returns whether they are equal.
658	pub fn eql(comptime T: type, a: []const T, b: []const T) bool {	658	pub fn eql(comptime T: type, a: []const T, b: []const T) bool {
659	if (@sizeOf(T) == 0) return true;	659	switch (@typeInfo(T)) {
		660	.Type, .ComptimeInt, .ComptimeFloat => {
		661	if (a.len != b.len) return false;
		662	inline for (a, b) \|a_elem, b_elem\| {
		663	if (a_elem != b_elem) return false;
		664	}
		665	return true;
		666	},
		667	.Null, .Undefined => return a.len == b.len,
		668	else => {},
		669	}
		670	if (@sizeOf(T) == 0) return a.len == b.len;
660	if (!@inComptime() and std.meta.hasUniqueRepresentation(T) and eqlBytes_allowed) return eqlBytes(sliceAsBytes(a), sliceAsBytes(b));	671	if (!@inComptime() and std.meta.hasUniqueRepresentation(T) and eqlBytes_allowed) return eqlBytes(sliceAsBytes(a), sliceAsBytes(b));
661		672
662	if (a.len != b.len) return false;	673	if (a.len != b.len) return false;
...	@@ -3296,6 +3307,26 @@ test eql {	...	@@ -3296,6 +3307,26 @@ test eql {
3296	try testing.expect(eql(u8, "abcd", "abcd"));	3307	try testing.expect(eql(u8, "abcd", "abcd"));
3297	try testing.expect(!eql(u8, "abcdef", "abZdef"));	3308	try testing.expect(!eql(u8, "abcdef", "abZdef"));
3298	try testing.expect(!eql(u8, "abcdefg", "abcdef"));	3309	try testing.expect(!eql(u8, "abcdefg", "abcdef"));
		3310
		3311	try testing.expect(eql(type, &.{ bool, f32 }, &.{ bool, f32 }));
		3312	try testing.expect(!eql(type, &.{ bool, f32 }, &.{ f32, bool }));
		3313	try testing.expect(!eql(type, &.{ bool, f32 }, &.{bool}));
		3314
		3315	try testing.expect(eql(comptime_int, &.{ 1, 2, 3 }, &.{ 1, 2, 3 }));
		3316	try testing.expect(!eql(comptime_int, &.{ 1, 2, 3 }, &.{ 3, 2, 1 }));
		3317	try testing.expect(!eql(comptime_int, &.{1}, &.{ 1, 2 }));
		3318
		3319	try testing.expect(eql(@TypeOf(undefined), &.{ undefined, undefined }, &.{ undefined, undefined }));
		3320	try testing.expect(!eql(@TypeOf(undefined), &.{undefined}, &.{ undefined, undefined }));
		3321
		3322	try testing.expect(eql(enum {}, &.{ undefined, undefined }, &.{ undefined, undefined }));
		3323	try testing.expect(!eql(enum {}, &.{undefined}, &.{ undefined, undefined }));
		3324
		3325	try testing.expect(eql(void, &.{ {}, {} }, &.{ {}, {} }));
		3326	try testing.expect(!eql(void, &.{{}}, &.{ {}, {} }));
		3327
		3328	try testing.expect(eql(@TypeOf(null), &.{ null, null }, &.{ null, null }));
		3329	try testing.expect(!eql(@TypeOf(null), &.{null}, &.{ null, null }));
3299	}	3330	}
3300		3331
3301	fn moreReadIntTests() !void {	3332	fn moreReadIntTests() !void {