namespace

 

#include <iostream>

using namespace std;


namespace MySpace1
{
	namespace InnerSpace
	{
		void my_function(){
			cout << "my_function" << endl;
		}
	}
	int doSomething(int a, int b) {
		return a + b;
	}
}

namespace MySpace2
{
	int doSomething(int a, int b) {
		return a + b;
	}
}


int main() {
	using namespace MySpace1;

	doSomething(3, 4);

	cout << MySpace2::doSomething(3, 4) << endl;

	InnerSpace::my_function();

}

 

cout, endl은 iostream에 들어있는 std 네임스페이스안의 것들!