std::unordered_multiset::contains

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C++
Containers library
std::unordered_multiset
Member functions
Iterators
Capacity
Modifiers
(C++17)
(C++17)
Lookup
unordered_multiset::contains
(C++20)
Bucket interface
Hash policy
Observers
Deduction guides(C++17)
bool contains( const Key& key ) const;
 (1) (since C++20)
1) Checks if there is an element with key equivalent to key in the container.

Parameters

key - key value of the element to search for


Return value

true if there is such an element, otherwise false.

Complexity

Constant on average, worst case linear in the size of the container.

Example

Run this code
#include <iostream>
#include <unordered_set>

int main()
{  
    std::unordered_multiset<int> example = {1, 2, 3, 4};

    if(example.contains(2)) {
        std::cout << "Found\n";
    } else {
        std::cout << "Not found\n";
    }
}

Output: 

Found

See also

 finds element with specific key
(public member function)
returns the number of elements matching specific key
(public member function)
returns range of elements matching a specific key
(public member function)
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