Function is_missing_required_utf_bom

utf8.c:646–657

}

int is_missing_required_utf_bom(const char *enc, const char *data, size_t len)
{
	return (
	   (same_utf_encoding(enc, "UTF-16")) &&
	   !(has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
	     has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
	) || (
	   (same_utf_encoding(enc, "UTF-32")) &&
	   !(has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
	     has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
	);
}

/*
 * Returns first character length in bytes for multi-byte `text` according to