C++ multimap empty()用法及代碼示例

// C++ program to demonstrate 
// std::multimap::empty 
  
#include <iostream> 
#include <map> 
  
using namespace std; 
  
int main() 
{ 
  
    // declaring multimap 
    multimap<char, int> mmap; 
  
    // checking if mmap is empty or not 
    if (mmap.empty()) 
        cout << "multimap is empty\n"; 
  
    // inserting values to mmap 
    // thus making it non empty 
    mmap.insert(pair<char, int>('a', 26)); 
    mmap.insert(pair<char, int>('b', 30)); 
    mmap.insert(pair<char, int>('c', 44)); 
  
    // checking that mmap is now not empty 
    if (mmap.empty()) 
        cout << "multimap is empty\n"; 
    else
        cout << "multimap is not empty\n"; 
  
    return 0; 
}