Abseil Common Libraries (C++) (grcp 依赖)
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52 lines
1.8 KiB
52 lines
1.8 KiB
7 years ago
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// Copyright 2017 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// UTF8 utilities, implemented to reduce dependencies.
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//
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// If you need Unicode specific processing (for example being aware of
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// Unicode character boundaries, or knowledge of Unicode casing rules,
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// or various forms of equivalence and normalization), take a look at
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// files in i18n/utf8.
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#ifndef ABSL_STRINGS_INTERNAL_UTF8_H_
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#define ABSL_STRINGS_INTERNAL_UTF8_H_
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#include <cstddef>
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#include <cstdint>
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namespace absl {
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namespace strings_internal {
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// For Unicode code points 0 through 0x10FFFF, EncodeUTF8Char writes
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// out the UTF-8 encoding into buffer, and returns the number of chars
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// it wrote.
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//
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// As described in https://tools.ietf.org/html/rfc3629#section-3 , the encodings
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// are:
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// 00 - 7F : 0xxxxxxx
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// 80 - 7FF : 110xxxxx 10xxxxxx
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// 800 - FFFF : 1110xxxx 10xxxxxx 10xxxxxx
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// 10000 - 10FFFF : 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
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//
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// Values greater than 0x10FFFF are not supported and may or may not write
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// characters into buffer, however never will more than kMaxEncodedUTF8Size
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// bytes be written, regardless of the value of utf8_char.
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enum { kMaxEncodedUTF8Size = 4 };
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size_t EncodeUTF8Char(char *buffer, char32_t utf8_char);
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} // namespace strings_internal
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} // namespace absl
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#endif // ABSL_STRINGS_INTERNAL_UTF8_H_
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