note: declarations in dependent base ‘std::basic_ios’ are not found by unqualified lookup

错误信息如题所示。

修改前：

 1  template<
 2     typename _CharT,
 3     typename _Traits = std::char_traits<_CharT>
 4   >
 5     class BasicStkIos
 6     : virtual public std::basic_ios<_CharT, _Traits>
 7     {
 8     public:
 9       typedef basic_stkbuf <_CharT,_Traits>        StkBufType;
10 
11       BasicStkIos()
12       : mBuf()
13       {init(&mBuf) ;};
14 
15       BasicStkIos(const char* fName, std::ios::openmode m, const char* pFilter)
16       : mBuf(fName, m, pFilter)
17       { init(&mBuf) ; }
18 
19       StkBufType*
20       rdbuf()
21       { return &mBuf; }
22 
23     protected:
24       StkBufType  mBuf;
25     };

修改后：

 1  template<
 2     typename _CharT,
 3     typename _Traits = std::char_traits<_CharT>
 4   >
 5     class BasicStkIos
 6     : virtual public std::basic_ios<_CharT, _Traits>
 7     {
 8     public:
 9       typedef basic_stkbuf <_CharT,_Traits>        StkBufType;
10 
11       BasicStkIos()
12       : mBuf()
13       {this->init(&mBuf) ;};
14 
15       BasicStkIos(const char* fName, std::ios::openmode m, const char* pFilter)
16       : mBuf(fName, m, pFilter)
17       { init(&mBuf) ; }
18 
19       StkBufType*
20       rdbuf()
21       { return &mBuf; }
22 
23     protected:
24       StkBufType  mBuf;
25     };