Size of empty class

[Fransje]

This code:

#include <iostream>

class Foo
{

};

int main()
{
    Foo foo;
    std::cout << sizeof ( foo ) << std::endl;

    std::cin.get();
    return ( 0 );
}

produces this result:

1

Why is the size of an instance of Foo 1, although it doesn't have any member variables?

[JLBorges]

Objects have identity; each object must have a unique address in memory.

For instance, these eleven objects must be distinguishable from each other:

Foo bar[10] ;
Foo baz ;

[Fransje]

Ah, that makes sense. Thanks!