text: // Tencent is pleased to support the open source community by making RapidJSON available.
  // 
  // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
  //
  // Licensed under the MIT License (the "License"); you may not use this file except
  // in compliance with the License. You may obtain a copy of the License at
  //
  // http://opensource.org/licenses/MIT
  //
  // 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.
  
  #ifndef RAPIDJSON_INTERNAL_STRFUNC_H_
  #define RAPIDJSON_INTERNAL_STRFUNC_H_
  
  #include "../stream.h"
  #include <cwchar>
  
  RAPIDJSON_NAMESPACE_BEGIN
  namespace internal {
  
  //! Custom strlen() which works on different character types.
  /*! \tparam Ch Character type (e.g. char, wchar_t, short)
      \param s Null-terminated input string.
      \return Number of characters in the string. 
      \note This has the same semantics as strlen(), the return value is not number of Unicode codepoints.
  */
  template <typename Ch>
  inline SizeType StrLen(const Ch* s) {
      RAPIDJSON_ASSERT(s != 0);
      const Ch* p = s;
      while (*p) ++p;
      return SizeType(p - s);
  }
  
  template <>
  inline SizeType StrLen(const char* s) {
      return SizeType(std::strlen(s));
  }
  
  template <>
  inline SizeType StrLen(const wchar_t* s) {
      return SizeType(std::wcslen(s));
  }
  
  //! Returns number of code points in a encoded string.
  template<typename Encoding>
  bool CountStringCodePoint(const typename Encoding::Ch* s, SizeType length, SizeType* outCount) {
      RAPIDJSON_ASSERT(s != 0);
      RAPIDJSON_ASSERT(outCount != 0);
      GenericStringStream<Encoding> is(s);
      const typename Encoding::Ch* end = s + length;
      SizeType count = 0;
      while (is.src_ < end) {
          unsigned codepoint;
          if (!Encoding::Decode(is, &codepoint))
              return false;
          count++;
      }
      *outCount = count;
      return true;
  }
  
  } // namespace internal
  RAPIDJSON_NAMESPACE_END
  
  #endif // RAPIDJSON_INTERNAL_STRFUNC_H_
  