ecency-mobile/ios/Pods/Folly/folly/Unicode.cpp

54 lines
1.7 KiB
C++

/*
* Copyright 2016 Facebook, Inc.
*
* 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
*
* http://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.
*/
#include <folly/Unicode.h>
namespace folly {
//////////////////////////////////////////////////////////////////////
std::string codePointToUtf8(char32_t cp) {
std::string result;
// Based on description from http://en.wikipedia.org/wiki/UTF-8.
if (cp <= 0x7f) {
result.resize(1);
result[0] = static_cast<char>(cp);
} else if (cp <= 0x7FF) {
result.resize(2);
result[1] = static_cast<char>(0x80 | (0x3f & cp));
result[0] = static_cast<char>(0xC0 | (cp >> 6));
} else if (cp <= 0xFFFF) {
result.resize(3);
result[2] = static_cast<char>(0x80 | (0x3f & cp));
result[1] = (0x80 | static_cast<char>((0x3f & (cp >> 6))));
result[0] = (0xE0 | static_cast<char>(cp >> 12));
} else if (cp <= 0x10FFFF) {
result.resize(4);
result[3] = static_cast<char>(0x80 | (0x3f & cp));
result[2] = static_cast<char>(0x80 | (0x3f & (cp >> 6)));
result[1] = static_cast<char>(0x80 | (0x3f & (cp >> 12)));
result[0] = static_cast<char>(0xF0 | (cp >> 18));
}
return result;
}
//////////////////////////////////////////////////////////////////////
}