ex19_18.cpp

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

int main(int argc, char *argv[])
{
	std::vector< std::string > v;
	std::string a;
	while (std::getline(std::cin,a)) {
		v.push_back(a);	
	}
	auto m = std::count_if(v.begin(),v.end(),std::mem_fn(&std::string::empty));
	std::cout << "Using mem_fn,the number of empty lines:" << m << std::endl;
	auto n = std::count_if(v.begin(),v.end(),std::bind(&std::string::empty,std::placeholders::_1));
	std::cout << "Using bind,the number of empty lines:" << n << std::endl;
	auto q = std::count_if(v.begin(),v.end(),[](std::string &tem){
			return tem.empty();
			});
	std::cout << "Using lamba,the number of empty lines:" << q << std::endl;
	return 0;
}