diff options
Diffstat (limited to 'lib/std')
| -rw-r--r-- | lib/std/meta.zig | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/lib/std/meta.zig b/lib/std/meta.zig index 7ec29dcd0e..7fe0df3dea 100644 --- a/lib/std/meta.zig +++ b/lib/std/meta.zig @@ -1094,6 +1094,36 @@ test "sizeof" { testing.expect(sizeof(c_void) == 1); } +pub const CIntLiteralRadix = enum { decimal, octal, hexadecimal }; + +fn PromoteIntLiteralReturnType(comptime SuffixType: type, comptime target: comptime_int, comptime radix: CIntLiteralRadix) type { + const signed_decimal = [_]type{ c_int, c_long, c_longlong }; + const signed_oct_hex = [_]type{ c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong }; + const unsigned = [_]type{ c_uint, c_ulong, c_ulonglong }; + + const list: []const type = if (@typeInfo(SuffixType).Int.signedness == .unsigned) + &unsigned + else if (radix == .decimal) + &signed_decimal + else + &signed_oct_hex; + + var pos = mem.indexOfScalar(type, list, SuffixType).?; + + while (pos < list.len) : (pos += 1) { + if (target >= math.minInt(list[pos]) and target <= math.maxInt(list[pos])) { + return list[pos]; + } + } + @compileError("Integer literal does not fit in compatible types"); +} + +/// Promote the type of an integer literal until it fits as C would. +/// This is for translate-c and is not intended for general use. +pub fn promoteIntLiteral(comptime SuffixType: type, comptime target: comptime_int, comptime radix: CIntLiteralRadix) PromoteIntLiteralReturnType(SuffixType, target, radix) { + return @as(PromoteIntLiteralReturnType(SuffixType, target, radix), target); +} + /// For a given function type, returns a tuple type which fields will /// correspond to the argument types. /// |