声明 Lambda 表达式

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auto f1 = [](int x, int y) { return x + y; };
cout << f1(2, 3) << endl; // 输出 5

function<int(int, int)> f2 = [](int x, int y) { return x + y; };
cout << f2(3, 4) << endl; // 输出 7
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#include <functional>
#include <iostream>

int main()
{
	using namespace std;
	
	int i = 3, j = 5;
	
	function<int (void)> f = [i, &j] { return i + j; };
	
	i = 22;
	j = 44;
	
	cout << f() << endl; // 3 + j = 47，输出 47
}

调用 Lambda 表达式

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#include <iostream>

int main()
{
	using namespace std;
	int n = [] (int x, int y) { return x + y; }(5, 4);
	cout << n << endl; // 输出 9
}
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// STL+Lambda 用法
#include <list>
#include <algorithm>
#include <iostream>

int main()
{
	using namespace std;
	
	list<int> numbers;
	numbers.push_back(13);
	numbers.push_back(17);
	numbers.push_back(42);
	numbers.push_back(46);
	numbers.push_back(99);
	
	const list<int>::const_iterator result =
	find_if(numbers.begin(), numbers.end(),[](int n) { return (n % 2) == 0; });
	
	if (result != numbers.end()) {
		cout << "The first even number in the list is " << *result << "." << endl; // 第一个偶数是 42
	} else {
		cout << "The list contains no even numbers." << endl;
	}
}

嵌套 Lambda 表达式

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#include <iostream>

int main()
{
	using namespace std;
	
	// The following lambda expression contains a nested lambda
	// expression.
	int timestwoplusthree = [](int x) { return [](int y) { return y * 2; }(x) + 3; }(5);
	
	// Print the result.
	cout << timestwoplusthree << endl;
}

高阶Lambda函数

https://msdn.microsoft.com/zh-cn/library/dd293599.aspx