Thread: Understanding this piece of code

Code:

//Code from my SystemClass!

bool SystemClass::Frame()
{
    bool result;


    //check if the user pressed escape and wants to exit the application.
    if (m_Input->IsKeyDown(VK_ESCAPE))
    {
        return false;
    }
}

//Code from my InputClass!
void InputClass::KeyDown(unsigned int input)
{
    // If a key is pressed then save that state in the key array.
    m_keys[input] = true;
    return;
}

I do not understand why my Frame function in my SystemClass is returning false. It is checking too see if the escape button is pressed, then why return false? Also what is returning false in this method...is it the m_Input?

I am a little confused, could someone please clarify

As Hodor says, if that condition is false, there is no return statement at the end of the function. This still compiles, because sometimes you don't want to generate code for every input of the function if you know that the function will only ever be called with a narrower set of inputs than allowed by the type system. However, it is undefined behavior to call the function with parameters that reach the end of a non-Void function without returning or throwing. So the compiler can assume that the function is only ever called with valid parameters, and optimise the function based on that assumption.

Some compilers will generate a predictable crash when this code is compiled in debug mode. But if you turn up optimisation, the Frame function will be optimized to always return false.