Help with a header file

[3qX21hU5]

So im quite new to header files and using more then one file in general. Ive heard that using a header file to place your functions in is a good idea usually so im doing that for a exercise that I have.

The problem that I have run into though is this


Header File

#ifndef FUNCTIONS_H_INCLUDED
#define FUNCTIONS_H_INCLUDED

#include <vector>
#include <iostream>
#include <string>
#include <stdexcept>
#include <algorithm>

// student_info is a stuct in my main.cpp
std::istream &read(std::istream &in, student_info &s)
{
    is >> s.name >> s.midterm >> s.final;

    read_hw(in, s.homework);
    return in;
}

#endif // FUNCTIONS_H_INCLUDED 

As you can see im getting a error because student_info isnt declared in this file, and I was wondering if I should #include "main.cpp" or if that would cause problems. Also if I have #include sting and other includes in both my main.cpp and functions.h files will that be a problem?
Thanks for the help with a kind of stupid question.

[Moschops]

It is generally a very bad idea to put your function definition in a header. It will cause a linker error if more than one cpp file includes the header (header guards have nothing to do with this particular error).

Put the function declaration in a header file. Put the function definition in one cpp file.


On to your particular problem. Never #include a cpp file. More carefully, don't do it unless you really, really know what you're doing.

Put the definition of the type student_info in a header file, and then #include that header file in each cpp and header file that needs to know what a student_info is.

[3qX21hU5]

Ahh ok thank you I think I got it all backwards.