swap 函数 (unordered_map)
交换两个容器的内容。
template<class Key, class Ty, class Hash, class Pred, class Alloc>
void swap(
unordered_map <Key, Ty, Hash, Pred, Alloc>& left,
unordered_map <Key, Ty, Hash, Pred, Alloc>& right);
参数
Key
键类型。Ty
映射类型。Hash
哈希函数对象类型。Pred
相等比较函数对象类型。Alloc
分配程序类。left
交换的第一个容器。right
交换的另一个容器。
备注
模板函数执行 left.unordered_map::swap(right)。
示例
// std_tr1__unordered_map__u_m_swap.cpp
// compile with: /EHsc
#include <unordered_map>
#include <iostream>
typedef std::unordered_map<char, int> Mymap;
int main()
{
Mymap c1;
c1.insert(Mymap::value_type('a', 1));
c1.insert(Mymap::value_type('b', 2));
c1.insert(Mymap::value_type('c', 3));
// display contents " [c 3] [b 2] [a 1]"
for (Mymap::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << it->first << ", " << it->second << "]";
std::cout << std::endl;
Mymap c2;
c2.insert(Mymap::value_type('d', 4));
c2.insert(Mymap::value_type('e', 5));
c2.insert(Mymap::value_type('f', 6));
c1.swap(c2);
// display contents " [f 6] [e 5] [d 4]"
for (Mymap::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << it->first << ", " << it->second << "]";
std::cout << std::endl;
swap(c1, c2);
// display contents " [c 3] [b 2] [a 1]"
for (Mymap::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << it->first << ", " << it->second << "]";
std::cout << std::endl;
return (0);
}
要求
标头: <unordered_map>
命名空间: std