Lambda表达式

标签：lambda   lambda表达式   

flyfish 

建立windows控制台应用程序

函数式写法

#include "stdafx.h"
#include <iostream>


int fun(int x, int y)
{
  return x + y;
}  
int _tmain(int argc, _TCHAR* argv[])
{


	std::wcout<<fun(1,2)<<std::endl;


	return 0;
}

#include "stdafx.h"
#include <iostream>


  
int _tmain(int argc, _TCHAR* argv[])
{
	auto var= [](int x, int y) { return x + y; };


	std::wcout<<var(1,2)<<std::endl;


	return 0;
}

#include <iostream>
#include "stdafx.h"


int _tmain(int argc, _TCHAR* argv[])
{


	int a = 3;


	auto var = [a] (int x, int y){ return a + x + y; };


	std::wcout <<var(10,20) << std::endl;
}

#include <iostream>
#include "stdafx.h"


int _tmain(int argc, _TCHAR* argv[])
{


	int a = 3;


	auto var = [&a] (int x, int y){ return a + x + y; };


	a = 4;


	std::wcout <<var(10,20) << std::endl;
}

输出34, 通过引用捕获 a，当a被重新赋值时就会影响该表达式的结果

3 捕获this指针，访问类的成员变量

#include "stdafx.h"
#include <algorithm>
#include <iostream>
#include <vector>




class CCalc 
{
public:


	explicit CCalc(int nFactor)
		: m_nFactor(nFactor)
	{
	}


	void fun(const std::vector<int>& v) const
	{
		std::for_each(v.begin(), v.end(),
			[this](int n) { std::wcout << n * m_nFactor << std::endl; });
	}


private:
	int m_nFactor;
};


int _tmain(int argc, _TCHAR* argv[])
{
	std::vector<int> v;
	v.push_back(1);
	v.push_back(2);


	CCalc o(10);
	o.fun(v);
}

Lambda表达式

标签：lambda   lambda表达式   

原文地址：http://blog.csdn.net/flyfish1986/article/details/39961969