fn decode_to_utf16_raw_impl(
dec: &mut VariantDecoder,
src: &[u8],
dst: &mut [u16],
last: bool,
) -> (DecoderResult, usize, usize)fn decode_to_utf16_raw_impl(
dec: &mut VariantDecoder,
src: &[u8],
dst: &mut [u16],
last: bool,
) -> (DecoderResult, usize, usize)