class A
{
	public:
		A( );
		explicit A( int a );
};

A::A( )
{
}

A::A( int a )
{
}

int main( )
{
	A *a = new A( 13 );
	A *b = new A( );
	A c;
	A d(13);
	// A e = 13; no implicit conversion possible !
	delete a;
	delete b;
}