al_utf16_encode - Allegro 5 API
size_t al_utf16_encode(uint16_t s, int32_t c)
Encode the specified code point to UTF-16 into the buffer s. The
buffer must have enough space to hold the encoding, which takes either
2 or 4 bytes. This routine will refuse to encode code points above
Returns the number of bytes written, which is the same as that
returned by al_utf16_width(3alleg5).