Why can I declare a float in a header file, but not a custom struct type?-CodePudding

Why can I declare a float like:

Player.h (compiles)


#include "Component.h"
#include "Vector2.h"

class Player : public Component
{
public:
    float positionX;
    float positionY;
};

but can't declare a my Vector2 struct like:

Player.h (does not compile)

#pragma once

#include "Component.h"
#include "Vector2.h"

class Player : public Component
{
public:
    Vector2 position;
};

Vector2.h

#pragma once

struct Vector2
{
    Vector2(float t_x, float t_y);

    float x;
    float y;
};

Vector2.cpp

#include "Vector2.h"

Vector2::Vector2(float t_x, float t_y)
{
    x = t_x;
    y = t_y;
}

I'm new to C so I might be doing something completely wrong, but I don't know what. I just want to declare a variable of type Vector2 to use inside of my Player.cpp file.

CodePudding user response：

If your Vector2 doesn't have a parameter-less constructor, C won't know how to construct it.

You need to declare how to construct your Vector2 in the Player constructor using parameter initialization, like so:

Player::Player() : position(0,0) {
    // player initialization here
}

Another option is to store an std::unique_ptr to your Vector2, leaving the initialization of the Vector2 at runtime.