C++:in namespace 'std' does not name a template type

对于类的声明的头文件,对于include它的任何一个文件,都需要将这个类内部声明的成员需要的头文件include进去。代码如下:

// hehe.h
#ifndef HEHE_H
#define HEHE_H
class Hehe{
public:
    Hehe() = default;
    void ShowSomthing();
    // do somthing 
private:
    std::vector<double> vec;
};
#endif  
  // hehe.cpp
  #include <iostream>
  #include "hehe.h"
  void Hehe::ShowSomthing(){
      std::cout << __func__ << std::endl;
  }
  // do somthing
// main.cpp
#include <iostream>
#include "hehe.h"
using namespace std;    
int main(){
    Hehe h;
    h.ShowSomething();
    return 0;
}

 

进行编译,由于main.cpp没有#include <vector>,将会报出错

In file included from hehe.cpp:2:0:
hehe.h:9:7: error: 'vector' in namespace 'std' does not name a template type
  std::vector<double> vec;
       ^~~~~~
In file included from main.cpp:2:0:
hehe.h:9:7: error: 'vector' in namespace 'std' does not name a template type
  std::vector<double> vec;
       ^~~~~~
main.cpp: In function 'int main()':
main.cpp:6:5: error: 'class Hehe' has no member named 'ShowSomething'; did you mean 'ShowSomthing'?
   h.ShowSomething();
     ^~~~~~~~~~~~~
     ShowSomthing

之后,对于main.cpp添加#include <vector>,通过

// main.cpp
#include <iostream>
#include <vector>
#include "hehe.h"
using namespace std;
int main(){
    Hehe h;
    h.ShowSomething();
    return 0;
}

 

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