What happens when a class and a function have the same name?

Question

#include <iostream>
using namespace std;

struct test
{
    test(){cout<<"class"<<endl;}
};
void test(){cout<<"function"<<endl;}

int main()
{
    test();
    return 0;
}

Output:

function  

(VS2013 ang gcc 4.8.1)

Why function is selected? Isn't it ambiguity?

Answer 1

This is called name hiding and described in

3.3 Scope [basic.scope]

3.3.1 Declarative regions and scopes [basic.scope.declarative]

4) Given a set of declarations in a single declarative region, each of which specifies the same unqualified name,
— they shall all refer to the same entity, or all refer to functions and function templates; or
— exactly one declaration shall declare a class name or enumeration name that is not a typedef name and the other declarations shall all refer to the same variable or enumerator, or all refer to functions and function templates; in this case the class name or enumeration name is hidden (3.3.10). [...]

emphasis mine.

Note that changing the order of declaration doesn't affect the outcome:

void test(){cout<<"function"<<endl;}

struct test
{
    test(){cout<<"class"<<endl;}
};

int main()
{
    test();
    return 0;
}

still prints out function.

In case it isn't obvious, don't do this :)