stl中map函数_map :: max_size（）函数，以及C ++ STL中的Example

stl中map函数

C ++ STL映射:: max_size() (C++ STL map::max_size() )

It returns the maximum number of elements the container(map) is able to hold but at runtime, the size of the container may be limited to a value smaller than specified by max_size() by the amount of RAM available. It gives us an only a theoretical limit on the size of the container.

它返回容器(映射)能够容纳的最大元素数量，但是在运行时，容器的大小可能会限制为小于可用max_size()指定的可用RAM数量的值。它仅对容器的大小提供了理论上的限制。

Syntax:

句法：

    myMap.max_size()

Where, myMap is the object of class map.

其中， myMap是类映射的对象。

Parameters: None - It does not accept any parameters.

参数：无-不接受任何参数。

Return value: It simply returns the maximum number of elements container can hold.

返回值：它仅返回容器可以容纳的最大元素数。

Example:

例：

#include <bits/stdc++.h> 
using namespace std; 
int main() 
{  
// create map container 
map<int, int> myMap;
//insert an element in map
myMap.insert( pair<int, int>(200 , 100) ); 
cout<<"max size of Non-empty map : \n"; 
cout << "The max size of myMap is " << myMap.max_size();
map<char,char> EmpMap;
map<int, int> EmpMap2; 
cout<<"max size of Empty-map : \n"; 
cout << "\nThe max size of EmpMap is " << EmpMap.max_size();
cout << "\nThe max size of EmpMap2 is " << EmpMap2.max_size();
return 0; 
}

Output

输出量

max size of Non-empty map :
The max size of myMap is 461168601842738790max size of Empty-map :
The max size of EmpMap is 461168601842738790
The max size of EmpMap2 is 461168601842738790