Make down-conversion explicit from CFX_Widetring to CFX_WideStringC.

core/fxcrt/include/fx_string.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_FXCRT_INCLUDE_FX_STRING_H_
 #define CORE_FXCRT_INCLUDE_FX_STRING_H_
 
 #include <stdint.h>  // For intptr_t.
@@ skipping 413 matching lines @@
   CFX_WideStringC(const FX_WCHAR* ptr, FX_STRSIZE len) {
     m_Ptr = ptr;
     m_Length = (len == -1) ? FXSYS_wcslen(ptr) : len;
   }
 
   CFX_WideStringC(const CFX_WideStringC& src) {
     m_Ptr = src.m_Ptr;
     m_Length = src.m_Length;
   }
 
-  CFX_WideStringC(const CFX_WideString& src);
-
   CFX_WideStringC& operator=(const FX_WCHAR* src) {
     m_Ptr = src;
     m_Length = FXSYS_wcslen(src);
     return *this;
   }
 
   CFX_WideStringC& operator=(const CFX_WideStringC& src) {
     m_Ptr = src.m_Ptr;
     m_Length = src.m_Length;
     return *this;
@@ skipping 104 matching lines @@
   static CFX_WideString FromLocal(const CFX_ByteString& str);
   static CFX_WideString FromCodePage(const CFX_ByteString& str,
                                      uint16_t codepage);
 
   static CFX_WideString FromUTF8(const char* str, FX_STRSIZE len);
   static CFX_WideString FromUTF16LE(const unsigned short* str, FX_STRSIZE len);
 
   static FX_STRSIZE WStringLength(const unsigned short* str);
 
   // Explicit conversion to C-style wide string.
+  // Note: |this| must outlive the use of the result.
   const FX_WCHAR* c_str() const { return m_pData ? m_pData->m_String : L""; }
 
   // Implicit conversion to C-style wide string -- deprecated.
+  // Note: |this| must outlive the use of the result.
   operator const FX_WCHAR*() const { return m_pData ? m_pData->m_String : L""; }
 
+  // Explicit conversion to CFX_WideStringC.
+  // Note: |this| must outlive the use of the result.
+  CFX_WideStringC AsWideStringC() const {
+    return CFX_WideStringC(c_str(), GetLength());
+  }
+
   void Empty();
-
   bool IsEmpty() const { return !GetLength(); }
   FX_STRSIZE GetLength() const { return m_pData ? m_pData->m_nDataLength : 0; }
 
   const CFX_WideString& operator=(const FX_WCHAR* str);
   const CFX_WideString& operator=(const CFX_WideString& stringSrc);
   const CFX_WideString& operator=(const CFX_WideStringC& stringSrc);
 
   const CFX_WideString& operator+=(const FX_WCHAR* str);
   const CFX_WideString& operator+=(FX_WCHAR ch);
   const CFX_WideString& operator+=(const CFX_WideString& str);
@@ skipping 101 matching lines @@
                   FX_STRSIZE nSrc2Len,
                   const FX_WCHAR* lpszSrc2Data);
   void AssignCopy(FX_STRSIZE nSrcLen, const FX_WCHAR* lpszSrcData);
   void AllocCopy(CFX_WideString& dest,
                  FX_STRSIZE nCopyLen,
                  FX_STRSIZE nCopyIndex) const;
 
   StringData* m_pData;
   friend class fxcrt_WideStringConcatInPlace_Test;
 };
-inline CFX_WideStringC::CFX_WideStringC(const CFX_WideString& src) {
-  m_Ptr = src.c_str();
-  m_Length = src.GetLength();
-}
+
 inline CFX_WideStringC& CFX_WideStringC::operator=(const CFX_WideString& src) {
   m_Ptr = src.c_str();
   m_Length = src.GetLength();
   return *this;
 }
 
 inline CFX_WideString operator+(const CFX_WideStringC& str1,
                                 const CFX_WideStringC& str2) {
   return CFX_WideString(str1, str2);
 }
 inline CFX_WideString operator+(const CFX_WideStringC& str1,
                                 const FX_WCHAR* str2) {
   return CFX_WideString(str1, str2);
 }
 inline CFX_WideString operator+(const FX_WCHAR* str1,
                                 const CFX_WideStringC& str2) {
   return CFX_WideString(str1, str2);
 }
 inline CFX_WideString operator+(const CFX_WideStringC& str1, FX_WCHAR ch) {
   return CFX_WideString(str1, CFX_WideStringC(ch));
 }
 inline CFX_WideString operator+(FX_WCHAR ch, const CFX_WideStringC& str2) {
   return CFX_WideString(ch, str2);
 }
 inline CFX_WideString operator+(const CFX_WideString& str1,
                                 const CFX_WideString& str2) {
-  return CFX_WideString(str1, str2);
+  return CFX_WideString(str1.AsWideStringC(), str2.AsWideStringC());
 }
 inline CFX_WideString operator+(const CFX_WideString& str1, FX_WCHAR ch) {
-  return CFX_WideString(str1, CFX_WideStringC(ch));
+  return CFX_WideString(str1.AsWideStringC(), CFX_WideStringC(ch));
 }
 inline CFX_WideString operator+(FX_WCHAR ch, const CFX_WideString& str2) {
-  return CFX_WideString(ch, str2);
+  return CFX_WideString(ch, str2.AsWideStringC());
 }
 inline CFX_WideString operator+(const CFX_WideString& str1,
                                 const FX_WCHAR* str2) {
-  return CFX_WideString(str1, str2);
+  return CFX_WideString(str1.AsWideStringC(), str2);
 }
 inline CFX_WideString operator+(const FX_WCHAR* str1,
                                 const CFX_WideString& str2) {
-  return CFX_WideString(str1, str2);
+  return CFX_WideString(str1, str2.AsWideStringC());
 }
 inline CFX_WideString operator+(const CFX_WideString& str1,
                                 const CFX_WideStringC& str2) {
-  return CFX_WideString(str1, str2);
+  return CFX_WideString(str1.AsWideStringC(), str2);
 }
 inline CFX_WideString operator+(const CFX_WideStringC& str1,
                                 const CFX_WideString& str2) {
-  return CFX_WideString(str1, str2);
+  return CFX_WideString(str1, str2.AsWideStringC());
 }
 inline bool operator==(const wchar_t* lhs, const CFX_WideString& rhs) {
   return rhs == lhs;
 }
 inline bool operator==(const CFX_WideStringC& lhs, const CFX_WideString& rhs) {
   return rhs == lhs;
 }
 inline bool operator!=(const wchar_t* lhs, const CFX_WideString& rhs) {
   return rhs != lhs;
 }
@@ skipping 10 matching lines @@
 }
 
 FX_FLOAT FX_atof(const CFX_ByteStringC& str);
 inline FX_FLOAT FX_atof(const CFX_WideStringC& wsStr) {
   return FX_atof(FX_UTF8Encode(wsStr.raw_str(), wsStr.GetLength()).c_str());
 }
 void FX_atonum(const CFX_ByteStringC& str, FX_BOOL& bInteger, void* pData);
 FX_STRSIZE FX_ftoa(FX_FLOAT f, FX_CHAR* buf);
 
 #endif  // CORE_FXCRT_INCLUDE_FX_STRING_H_