const typename in_utf_t::codepoint_t *src_next = in_utf_t::next (src, src_end, &unicode, replacement);
typename out_utf_t::codepoint_t *dst_next = out_utf_t::encode (dst, dst_end, unicode);
if (dst_next == dst)
const typename in_utf_t::codepoint_t *src_next = in_utf_t::next (src, src_end, &unicode, replacement);
typename out_utf_t::codepoint_t *dst_next = out_utf_t::encode (dst, dst_end, unicode);
if (dst_next == dst)