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; }