Compares two WTF16 strings using the equivalent functionality of
RtlEqualUnicodeString (with case insensitive comparison enabled).
This function can be called on any target.
pub fn eqlIgnoreCaseWtf16(a: []const u16, b: []const u16) boolpub fn eqlIgnoreCaseWtf16(a: []const u16, b: []const u16) bool {
if (@inComptime() or builtin.os.tag != .windows) {
// This function compares the strings code unit by code unit (aka u16-to-u16),
// so any length difference implies inequality. In other words, there's no possible
// conversion that changes the number of WTF-16 code units needed for the uppercase/lowercase
// version in the conversion table since only codepoints <= max(u16) are eligible
// for conversion at all.
if (a.len != b.len) return false;
for (a, b) |a_c, b_c| {
// The slices are always WTF-16 LE, so need to convert the elements to native
// endianness for the uppercasing
const a_c_native = std.mem.littleToNative(u16, a_c);
const b_c_native = std.mem.littleToNative(u16, b_c);
if (a_c != b_c and toUpperWtf16(a_c_native) != toUpperWtf16(b_c_native)) {
return false;
}
}
return true;
}
// Use RtlEqualUnicodeString on Windows when not in comptime to avoid including a
// redundant copy of the uppercase data.
return ntdll.RtlEqualUnicodeString(&.init(a), &.init(b), .TRUE).toBool();
}