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// 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. 
 
#include "y_absl/strings/internal/utf8.h"
 
namespace y_absl {
ABSL_NAMESPACE_BEGIN
namespace strings_internal { 
 
size_t EncodeUTF8Char(char *buffer, char32_t utf8_char) { 
  if (utf8_char <= 0x7F) { 
    *buffer = static_cast<char>(utf8_char); 
    return 1; 
  } else if (utf8_char <= 0x7FF) { 
    buffer[1] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[0] = 0xC0 | utf8_char; 
    return 2; 
  } else if (utf8_char <= 0xFFFF) { 
    buffer[2] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[1] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[0] = 0xE0 | utf8_char; 
    return 3; 
  } else { 
    buffer[3] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[2] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[1] = 0x80 | (utf8_char & 0x3F); 
    utf8_char >>= 6; 
    buffer[0] = 0xF0 | utf8_char; 
    return 4; 
  } 
} 
 
}  // namespace strings_internal 
ABSL_NAMESPACE_END
}  // namespace y_absl