Add missing operators for CFX_WideStringC.

core/include/fxcrt/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 _FX_STRING_H_
 #define _FX_STRING_H_
 
 #include <algorithm>
@@ skipping 423 matching lines @@
     return CFX_ByteString(str1, str2);
 }
 inline CFX_ByteString operator + (const CFX_ByteString& str1, FX_BSTR str2)
 {
     return CFX_ByteString(str1, str2);
 }
 inline CFX_ByteString operator + (FX_BSTR str1, const CFX_ByteString& str2)
 {
     return CFX_ByteString(str1, str2);
 }
-class CFX_WideStringC 
+class CFX_WideStringC
 {
 public:
     typedef FX_WCHAR value_type;
 
     CFX_WideStringC()
     {
         m_Ptr = NULL;
         m_Length = 0;
     }
 
@@ skipping 101 matching lines @@
     CFX_WideStringC     Right(FX_STRSIZE count) const
     {
         if (count < 1) {
             return CFX_WideStringC();
         }
         if (count > m_Length) {
             count = m_Length;
         }
         return CFX_WideStringC(m_Ptr + m_Length - count, count);
     }
+
+    const FX_WCHAR& operator[] (size_t index) const
+    {
+        return m_Ptr[index];
+    }
+
+    bool operator< (const CFX_WideStringC& that) const
+    {
+        int result = wmemcmp(m_Ptr, that.m_Ptr, std::min(m_Length, that.m_Length));
+        return result < 0 || (result == 0 && m_Length < that.m_Length);
+     }
+
 protected:
+    FX_LPCWSTR          m_Ptr;
+    FX_STRSIZE          m_Length;
 
-    FX_LPCWSTR          m_Ptr;
-
-    FX_STRSIZE          m_Length;
 private:
-
     void*                       operator new (size_t) throw()
     {
         return NULL;
     }
 };
 typedef const CFX_WideStringC&  FX_WSTR;
 #define FX_WSTRC(wstr) CFX_WideStringC(wstr, FX_ArraySize(wstr) - 1)
 struct CFX_StringDataW {
 
     long                m_nRefs;
@@ skipping 246 matching lines @@
 CFX_ByteString  FX_UTF8Encode(FX_LPCWSTR pwsStr, FX_STRSIZE len);
 inline CFX_ByteString   FX_UTF8Encode(FX_WSTR wsStr)
 {
     return FX_UTF8Encode(wsStr.GetPtr(), wsStr.GetLength());
 }
 inline CFX_ByteString   FX_UTF8Encode(const CFX_WideString &wsStr)
 {
     return FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength());
 }
 #endif