Does overloading parenthesis () effect constructor call?

Question

i have little query about () operator overloading. And my question is:

1. Does overloading parenthesis () effect constructor call?
2. If it will effect means shall i do some pre/post processing before my constructor/destructor call?
3. If question 2 is possible means what are the things shall i pre/post process and what should not?

If u feel this is duplicate of any other question or not correct way to ask this means also comment over here. Thanks in advance....

Answer 1

Question:

Does overloading parenthesis () effect constructor call?

No, it does not. The operator() function can be used with an object. The constructors use the class/struct name. Example:

struct Foo
{
    Foo() {}
    int operator()(){return 10;}
};

Foo foo = Foo(); // The constructor gets called.
foo();           // The operator() function gets called.

Foo foo2 = foo(); // Syntax error. Cannot use the return value of foo()
                  // to construct a Foo.
int i = foo();    // OK.

Answer 2

It will not interfer with the constructor calls. The reason is that a constructor call works on the type or while constructing an instance, while operator() works on a already constructed instance of the type.

Example:

struct A
{
    A(int) {}
    void operator()(int) {}
};

int main()
{
    A(42); // calls the constructor A::A(int)

    A a(42); // also calls A::A(int)
    a(42); // calls A::operator(int)
}