// Copyright 2017 The Abseil Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // // UTF8 utilities, implemented to reduce dependencies. #ifndef ABSL_STRINGS_INTERNAL_UTF8_H_ #define ABSL_STRINGS_INTERNAL_UTF8_H_ #include <cstddef> #include <cstdint> #include "absl/base/config.h" namespace absl { ABSL_NAMESPACE_BEGIN namespace strings_internal { // For Unicode code points 0 through 0x10FFFF, EncodeUTF8Char writes // out the UTF-8 encoding into buffer, and returns the number of chars // it wrote. // // As described in https://tools.ietf.org/html/rfc3629#section-3 , the encodings // are: // 00 - 7F : 0xxxxxxx // 80 - 7FF : 110xxxxx 10xxxxxx // 800 - FFFF : 1110xxxx 10xxxxxx 10xxxxxx // 10000 - 10FFFF : 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx // // Values greater than 0x10FFFF are not supported and may or may not write // characters into buffer, however never will more than kMaxEncodedUTF8Size // bytes be written, regardless of the value of utf8_char. enum { kMaxEncodedUTF8Size = 4 }; size_t EncodeUTF8Char(char *buffer, char32_t utf8_char); } // namespace strings_internal ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_STRINGS_INTERNAL_UTF8_H_