From 19cec0db1e8a9fefd8295c81edb03d631c624e62 Mon Sep 17 00:00:00 2001 From: LemonBoy Date: Sun, 25 Apr 2021 16:49:21 +0200 Subject: std: Make met.alignment work on more types Make it return the correct value for function types and optional pointers. --- lib/std/meta.zig | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'lib/std') diff --git a/lib/std/meta.zig b/lib/std/meta.zig index c6f800ca2c..9bb02013e6 100644 --- a/lib/std/meta.zig +++ b/lib/std/meta.zig @@ -117,10 +117,21 @@ test "std.meta.bitCount" { testing.expect(bitCount(f32) == 32); } +/// Returns the alignment of type T. +/// Note that if T is a pointer or function type the result is different than +/// the one returned by @alignOf(T). +/// If T is a pointer type the alignment of the type it points to is returned. +/// If T is a function type the alignment a target-dependent value is returned. pub fn alignment(comptime T: type) comptime_int { - //@alignOf works on non-pointer types - const P = if (comptime trait.is(.Pointer)(T)) T else *T; - return @typeInfo(P).Pointer.alignment; + return switch (@typeInfo(T)) { + .Optional => |info| switch (@typeInfo(info.child)) { + .Pointer, .Fn => alignment(info.child), + else => @alignOf(T), + }, + .Pointer => |info| info.alignment, + .Fn => |info| info.alignment, + else => @alignOf(T), + }; } test "std.meta.alignment" { @@ -129,6 +140,8 @@ test "std.meta.alignment" { testing.expect(alignment(*align(2) u8) == 2); testing.expect(alignment([]align(1) u8) == 1); testing.expect(alignment([]align(2) u8) == 2); + testing.expect(alignment(fn () void) > 0); + testing.expect(alignment(fn () align(128) void) == 128); } pub fn Child(comptime T: type) type { -- cgit v1.2.3