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authordaurnimator <quae@daurnimator.com>2020-03-05 15:59:19 +1100
committerdaurnimator <quae@daurnimator.com>2020-03-05 16:00:19 +1100
commit488ba1560fb80c1115b3b4794031859c0063ba3e (patch)
tree9a83d6820cc0788fb64511691c0f2789aebdfd55 /lib/std/math.zig
parent4f58bfe1a81a385ac9120510b816ff081ab73437 (diff)
downloadzig-488ba1560fb80c1115b3b4794031859c0063ba3e.tar.gz
zig-488ba1560fb80c1115b3b4794031859c0063ba3e.zip
std: fix math.absCast on i1
Diffstat (limited to 'lib/std/math.zig')
-rw-r--r--lib/std/math.zig36
1 files changed, 24 insertions, 12 deletions
diff --git a/lib/std/math.zig b/lib/std/math.zig
index 9a1143a17d..a411b58fac 100644
--- a/lib/std/math.zig
+++ b/lib/std/math.zig
@@ -670,23 +670,35 @@ 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(i1, -1)) == 1);
+
testing.expect(absCast(@as(i32, -999)) == 999);
testing.expect(@TypeOf(absCast(@as(i32, -999))) == u32);