Question

在我试图汇编模板类别时,我发现以下错误:

C.cpp: In member function  void PeriodContainerAdvanced<T>::add() :
C.cpp:133: error: type/value mismatch at argument 1 in template parameter list for  template<class _T1, class _T2> struct std::pair 
C.cpp:133: error:   expected a type, got  std::map<int,T,std::less<int>,std::allocator<std::pair<const int, T> > >::iterator 
C.cpp:133: error: invalid type in declaration before  ;  token

C.h档案中的班级:(简化)

template <class T>
class PeriodContainerAdvanced 
{
[skip]
    void add (); 
[skip]
}

C.cpp(简化):

template <class T>
void PeriodContainerAdvanced<T>::add()
{
[skip]
    std::pair<std::map< time_t, T >::iterator, bool> ret; // line 133 !
[skip]
}

And the similar error at other function when trying to define

std::map< time_t, T >::iterator it, it_start, it_end; // line 153

之后,编辑们说:

C.cpp:153: error: expected `;  before  it 
C.cpp:166: error:  it_start  was not declared in this scope

How to fix it? thanks

Answer 1

这名受扶养者的姓名需要宣布为:

std::pair<typename std::map< time_t, T >::iterator, bool> ret;

此外,为了避免日后的链接错误,你应将模板执行移至所有使用该模板的翻译单位的档案中,就像你界定你的模板类别时的负责人一样。

Answer 2

首先,需要将<代码>add(>>的实施工作列入标题档案或列入标题的档案。汇编者需要看到该守则,以便立即公布一个<代码>的模板。 T。

Second, the source of the error you quote, you need to add a typename to tell the compiler you are talking about a type. std::map< time_t, T >::iterator could be interpreted as a value.

template <class T>
class PeriodContainerAdvanced {
  void add () {
    std::pair<typename std::map< time_t, T >::iterator, bool> ret;
    ....         ^
  }
};

友情链接