Returns index of next character. If exact fit, returned index equals output slice length. Assumes there is enough space for the output.
pub fn utf8ToUtf16Le(utf16le: []u16, utf8: []const u8) error
pub fn utf8ToUtf16Le(utf16le: []u16, utf8: []const u8) error{InvalidUtf8}!usize {
return utf8ToUtf16LeImpl(utf16le, utf8, .cannot_encode_surrogate_half);
}