Return instance by value from a method stack compilation

Question

Can you explain why this won't compile:

(this is the error:

../Man.cpp:33:9: error: conversion from ‘Man (*)()’ to non-scalar type ‘Man’ requested)

Code:

Man goo(){
  Man m();
  return m;
}

but this does:

Man goo(){
    return Man();
}

Answer 1

Man m();

This means "somewhere else in the program, I will define a function named m that takes no arguments and returns a Man". Yes, even when you write it inside another function.

Man m;

This means "m is a variable of type Man". Since Man is a class type, the default constructor will be called and no parentheses are necessary.

Answer 2

You don't want those parentheses in your first example:

Man goo(){
  Man m;
  return m;
}

Answer 3

You don't need () in the first case. The default constructor is called implicitly.

Man goo(){
    Man m;
    return m; 
}

In the second case you are calling the constructor.