CODEWITHSUNDEEP
c++arraysstructmember-functions
Lorenz Leitner
Lorenz Leitner

Reputation: 591

How to pass a dynamic array of structs to a member function?

I am wondering how I can pass a dynamically allocated array of structures from the main function to a member function of a class. I don't necessarily need to change its values in the member function, just print it.

If I do it like I would with an integer array in the following code snippet, I get that MyStruct is not defined in the MyClass.h and MyClass.cpp files. (Which makes sense)
If I include main.cpp in MyClass.h I get a lot of weird errors. Another idea was prepending struct in the member function parameter, but that lead to other errors as well.

I need to declare the struct array outside of the class, not as a member, and I cannot use STL containers.

main.cpp: 

#include "MyClass.h"

int main()
{
    MyClass my_class;

    struct MyStruct
    {
        int a;
        int b;
    };

    MyStruct* struct_array = new MyStruct[4];
    // Fill struct array with values...
    my_class.printStructArray(struct_array);
}

MyClass.h: 

#include <iostream>
class MyClass
{
    // ...
    void printStructArray(MyStruct* struct_array);
};

MyClass.cpp: 

#include "MyClass.h"

void MyClass::printStructArray(MyStruct* struct_array)
{
    std::cout << struct_array[0].a << struct_array[0].b;
    // ...
}

Upvotes: 1

Views: 1137

Answers (1)

prajmus
prajmus

Reputation: 3271

Just move the struct definition into MyClass.h or it's own separate header file:

MyClass.h

#include <iostream>

struct MyStruct {
  int a, b;
};
class MyClass {
  // ...
  void printStructArray(MyStruct* struct_array);
};

Upvotes: 1

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