Question

I dont understand, why is the aaa operator called in the 2nd last line?

#include <iostream>

class MyClass
{
private:
    typedef void (MyClass::*aaa)() const;
    void ThisTypeDoesNotSupportComparisons() const {}
public:
    operator aaa() const { return (true) ? &MyClass::ThisTypeDoesNotSupportComparisons : 0; }
};

int main()
{
    MyClass a;
    MyClass b;

    if(a && b) {}
}

Answer 1

The compiler searches for the best match for (a && b).

Because the class doesn’t have an operator that turns MyClass to a boolean, it searches for the best cast.

operator aaa() const is a cast to an aaa type pointer. Pointers can be evaluated in an if sentence.

Overloading typecasts

Conversion Functions (C++)