1// Copyright 2017 The Abseil Authors.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// https://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14//
15// UTF8 utilities, implemented to reduce dependencies.
16
17#ifndef ABSL_STRINGS_INTERNAL_UTF8_H_
18#define ABSL_STRINGS_INTERNAL_UTF8_H_
19
20#include <cstddef>
21#include <cstdint>
22
23namespace absl {
24namespace strings_internal {
25
26// For Unicode code points 0 through 0x10FFFF, EncodeUTF8Char writes
27// out the UTF-8 encoding into buffer, and returns the number of chars
28// it wrote.
29//
30// As described in https://tools.ietf.org/html/rfc3629#section-3 , the encodings
31// are:
32// 00 - 7F : 0xxxxxxx
33// 80 - 7FF : 110xxxxx 10xxxxxx
34// 800 - FFFF : 1110xxxx 10xxxxxx 10xxxxxx
35// 10000 - 10FFFF : 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
36//
37// Values greater than 0x10FFFF are not supported and may or may not write
38// characters into buffer, however never will more than kMaxEncodedUTF8Size
39// bytes be written, regardless of the value of utf8_char.
40enum { kMaxEncodedUTF8Size = 4 };
41size_t EncodeUTF8Char(char *buffer, char32_t utf8_char);
42
43} // namespace strings_internal
44} // namespace absl
45
46#endif // ABSL_STRINGS_INTERNAL_UTF8_H_
47