diff options
Diffstat (limited to 'lib/std/math.zig')
| -rw-r--r-- | lib/std/math.zig | 49 |
1 files changed, 27 insertions, 22 deletions
diff --git a/lib/std/math.zig b/lib/std/math.zig index 9a1143a17d..ed13e3cd27 100644 --- a/lib/std/math.zig +++ b/lib/std/math.zig @@ -670,33 +670,38 @@ fn testRem() void { /// Returns the absolute value of the integer parameter. /// Result is an unsigned integer. -pub fn absCast(x: var) t: { - if (@TypeOf(x) == comptime_int) { - break :t comptime_int; - } else { - break :t std.meta.IntType(false, @TypeOf(x).bit_count); +pub fn absCast(x: var) switch(@typeInfo(@TypeOf(x))) { + .ComptimeInt => comptime_int, + .Int => |intInfo| std.meta.IntType(false, intInfo.bits), + else => @compileError("absCast only accepts integers"), } -} { - if (@TypeOf(x) == comptime_int) { - return if (x < 0) -x else x; +{ + switch(@typeInfo(@TypeOf(x))) { + .ComptimeInt => { + if (x < 0) { + return -x; + } else { + return x; + } + }, + .Int => |intInfo| { + const Uint = std.meta.IntType(false, intInfo.bits); + if (x < 0) { + return ~@bitCast(Uint, x +% -1); + } else { + return @intCast(Uint, x); + } + }, + else => unreachable, } - const uint = std.meta.IntType(false, @TypeOf(x).bit_count); - if (x >= 0) return @intCast(uint, x); - - return @intCast(uint, -(x + 1)) + 1; } test "math.absCast" { - testing.expect(absCast(@as(i32, -999)) == 999); - testing.expect(@TypeOf(absCast(@as(i32, -999))) == u32); - - testing.expect(absCast(@as(i32, 999)) == 999); - testing.expect(@TypeOf(absCast(@as(i32, 999))) == u32); - - testing.expect(absCast(@as(i32, minInt(i32))) == -minInt(i32)); - testing.expect(@TypeOf(absCast(@as(i32, minInt(i32)))) == u32); - - testing.expect(absCast(-999) == 999); + testing.expectEqual(@as(u1, 1), absCast(@as(i1, -1))); + testing.expectEqual(@as(u32, 999), absCast(@as(i32, -999))); + testing.expectEqual(@as(u32, 999), absCast(@as(i32, 999))); + testing.expectEqual(@as(u32, -minInt(i32)), absCast(@as(i32, minInt(i32)))); + testing.expectEqual(999, absCast(-999)); } /// Returns the negation of the integer parameter. |
