#include <iostream>
#include <cstdlib>
#include <string>          //for class string
#include <algorithm>       //for find_if
#include <functional>      //for bind2nd, mem_fun_ref
#include <ext/functional>  //for compose1
using namespace std;

int main()
{
	const string a[] = {"", "hello", "goodbye"};
	const size_t n = sizeof a / sizeof a[0];

	const string *p = find_if(a, a + n, mem_fun_ref(&string::size));

	if (p == a + n) {
		cout << "Every string was of length 0.\n";
	} else {
		cout << "The first non-empty string was a["
			<< p - a << "] == \"" << *p << "\".\n";
	}

	p = find_if(a, a + n,
		__gnu_cxx::compose1(
			bind2nd(equal_to<string::size_type>(), 7),
			mem_fun_ref(&string::size)
		)
	);

	if (p == a + n) {
		cout << "No string was of length 7.\n";
	} else {
		cout << "The first string of length 7 was a["
			<< p - a << "] == \"" << *p << "\".\n";
	}

	return EXIT_SUCCESS;
}