#include <iostream>
#include <algorithm>
#include <functional>
#include <iterator>
#include <vector>
#include <string>

bool check_sz(const std::string &s, std::string::size_type sz)
{
	return s.size() == sz;
}

int main()
{
	int sz = 4;
	std::vector<std::string> v = { "x", "zzz", "yy", "tttt" };

	auto check = std::bind(check_sz, _1, 3);
}