std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::erase

 

C++

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Named requirements

Feature test macros (C++20)

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Concepts library (C++20)

Metaprogramming library (C++11)

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Containers library

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Ranges library (C++20)

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Filesystem library (C++17)

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Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::flat_multimap

Member types

Member functions

flat_multimap::flat_multimap    flat_multimap::operator= Modifiers flat_multimap::clear flat_multimap::erase flat_multimap::swap flat_multimap::extract flat_multimap::replace flat_multimap::insert flat_multimap::insert_range flat_multimap::emplace flat_multimap::emplace_hint Lookup flat_multimap::count flat_multimap::find flat_multimap::contains flat_multimap::equal_range flat_multimap::lower_bound flat_multimap::upper_bound Iterators flat_multimap::beginflat_multimap::cbegin flat_multimap::endflat_multimap::cend flat_multimap::rbeginflat_multimap::crbegin flat_multimap::rendflat_multimap::crend Capacity flat_multimap::size flat_multimap::max_size flat_multimap::empty Observers flat_multimap::key_comp flat_multimap::keys flat_multimap::value_comp flat_multimap::values

Non-member functions

swap(std::flat_multimap) erase_if(std::flat_multimap)     operator==operator<=>

Helper classes

uses_allocator<std::flat_multimap>

Tags

sorted_equivalent          sorted_equivalent_t

Deduction guides

 

iterator erase( iterator position );	(1)	(since C++23)
iterator erase( const_iterator pos );	(2)	(since C++23)
iterator erase( const_iterator first, const_iterator last );	(3)	(since C++23)
size_type erase( const Key& key );	(4)	(since C++23)
template< class K > size_type erase( K&& x );	(5)	(since C++23)

Removes specified elements from the container. The order of the remaining equivalent elements is preserved.

1,2) Removes the element at pos.

3) Removes the elements in the range [first, last), which must be a valid range in *this.

4) Removes all elements with the key equivalent to key.

5) Removes all elements with key that compares equivalent to the value x. This overload participates in overload resolution only if the qualified-id Compare::is_transparent is valid and denotes a type, and neither iterator nor const_iterator is implicitly convertible from K. It allows calling this function without constructing an instance of Key.

The iterator pos must be valid and dereferenceable. Thus the end() iterator (which is valid, but is not dereferenceable) cannot be used as a value for pos.

Parameters

pos	-	iterator to the element to remove
first, last	-	range of elements to remove
key	-	key value of the elements to remove
x	-	a value of any type that can be transparently compared with a key denoting the elements to remove

Return value

1-3) Iterator following the last removed element.

4) Number of elements removed.

5) Number of elements removed.

Exceptions

1-3) Throws nothing.

4,5) Any exceptions thrown by the Compare object.

Complexity

Depends on underlying containers. Typically linear.

Example

Run this code

#include <flat_map>
#include <iostream>
 
int main()
{
    std::flat_multimap<int, std::string> c =
    {
        {1, "one"}, {2, "two"}, {3, "three"},
        {4, "four"}, {5, "five"}, {6, "six"}
    };
 
    // erase all odd numbers from c
    for (auto it = c.begin(); it != c.end();)
    {
        if (it->first % 2 != 0)
            it = c.erase(it);
        else
            ++it;
    }
 
    for (auto& p : c)
        std::cout << p.second << ' ';
    std::cout << '\n';
}

Output:

two four six

See also

clear

clears the contents (public member function)