text: /*
   *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #ifndef RTC_BASE_STRING_UTILS_H_
  #define RTC_BASE_STRING_UTILS_H_
  
  #include <ctype.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <string.h>
  
  #if defined(WEBRTC_WIN)
  #include <malloc.h>
  #include <wchar.h>
  #include <windows.h>
  
  #endif  // WEBRTC_WIN
  
  #if defined(WEBRTC_POSIX)
  #include <stdlib.h>
  #include <strings.h>
  #endif  // WEBRTC_POSIX
  
  #include <string>
  
  namespace rtc {
  
  const size_t SIZE_UNKNOWN = static_cast<size_t>(-1);
  
  // Safe version of strncpy that always nul-terminate.
  size_t strcpyn(char* buffer,
                 size_t buflen,
                 const char* source,
                 size_t srclen = SIZE_UNKNOWN);
  
  ///////////////////////////////////////////////////////////////////////////////
  // UTF helpers (Windows only)
  ///////////////////////////////////////////////////////////////////////////////
  
  #if defined(WEBRTC_WIN)
  
  inline std::wstring ToUtf16(const char* utf8, size_t len) {
    if (len == 0)
      return std::wstring();
    int len16 = ::MultiByteToWideChar(CP_UTF8, 0, utf8, static_cast<int>(len),
                                      nullptr, 0);
    std::wstring ws(len16, 0);
    ::MultiByteToWideChar(CP_UTF8, 0, utf8, static_cast<int>(len), &*ws.begin(),
                          len16);
    return ws;
  }
  
  inline std::wstring ToUtf16(const std::string& str) {
    return ToUtf16(str.data(), str.length());
  }
  
  inline std::string ToUtf8(const wchar_t* wide, size_t len) {
    if (len == 0)
      return std::string();
    int len8 = ::WideCharToMultiByte(CP_UTF8, 0, wide, static_cast<int>(len),
                                     nullptr, 0, nullptr, nullptr);
    std::string ns(len8, 0);
    ::WideCharToMultiByte(CP_UTF8, 0, wide, static_cast<int>(len), &*ns.begin(),
                          len8, nullptr, nullptr);
    return ns;
  }
  
  inline std::string ToUtf8(const wchar_t* wide) {
    return ToUtf8(wide, wcslen(wide));
  }
  
  inline std::string ToUtf8(const std::wstring& wstr) {
    return ToUtf8(wstr.data(), wstr.length());
  }
  
  #endif  // WEBRTC_WIN
  
  // Remove leading and trailing whitespaces.
  std::string string_trim(const std::string& s);
  
  // TODO(jonasolsson): replace with absl::Hex when that becomes available.
  std::string ToHex(const int i);
  
  std::string LeftPad(char padding, unsigned length, std::string s);
  
  }  // namespace rtc
  
  #endif  // RTC_BASE_STRING_UTILS_H_
  