C++tuple快速而随意的数据结构

初始化

	//<学号，姓名，年龄>
	tuple<unsigned, string, unsigned> t1; //t1 = (0, "", 0)
	tuple<unsigned, string, unsigned> t2(1, "张三", 18); //t2 = (1, "张三", 18)
	auto t3 = make_tuple(2, "李四", 21); //t3 = (2, "李四", 21)

其他功能

关系运算符

	bool s1 = (t2 == t1); //s1 = false
	bool s2 = (t2 != t1); //s2 = true
	bool s3 = (t2 < t1); //s3 = false
	bool s4 = (t2 > t1); //s4 = true

随机访问；尖括号的值必须是常量表达式；传入的值是左值，返回左值引用，否则，返回右值引用。

	auto id = get<0>(t2); //id = 1
	auto name = get<1>(t2); //name = "张三"
	auto age = get<2>(t2); //age = 18

重命名t2的类型，两种方法，前者为C++11新规

	//using type = decltype(t2);
	typedef tuple<unsigned, string, unsigned> type;

获取成员数量

	size_t s5 = tuple_size<type>::value; //s5 = 3

获取某个成员的类型

	tuple_element<1, type>::type name2 = get<1>(t2); //name2 = "张三"

详细内容请看C++Primer第17章 17.1 部分
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