std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::operator=

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

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

 

flat_multimap& operator=( const flat_multimap& other );	(1)	(since C++23) (implicitly declared)
flat_multimap& operator=( flat_multimap&& other );	(2)	(since C++23) (implicitly declared)
flat_multimap& operator=( std::initializer_list<value_type> ilist );	(3)	(since C++23)

Replaces the contents of the container adaptor with the contents of given argument.

1) Copy assignment operator. Replaces the contents with a copy of the contents of other. Effectively calls c = other.c; comp = other.comp;.

2) Move assignment operator. Replaces the contents with those of other using move semantics. Effectively calls c = std::move(other.c); comp = std::move(other.comp);.

3) Replaces the contents with those identified by initializer list ilist.

Parameters

other	-	another container adaptor to be used as source
ilist	-	initializer list to be used as source

Return value

*this

Complexity

1,2) Equivalent to that of operator= of the underlying container.

3) Linear in the size of *this and ilist.

Example

Run this code

#include <flat_map>
#include <initializer_list>
#include <print>
#include <utility>
 
int main()
{
    std::flat_multimap<int, int> x{{1, 1}, {2, 2}, {3, 3}}, y, z;
    const auto w = {std::pair<const int, int>{4, 4}, {5, 5}, {6, 6}, {7, 7}};
 
    std::println("Initially:");
    std::println("x = {}", x);
    std::println("y = {}", y);
    std::println("z = {}", z);
 
    y = x; // overload (1)
    std::println("Copy assignment copies data from x to y:");
    std::println("x = {}", x);
    std::println("y = {}", y);
 
    z = std::move(x); // overload (2)
    std::println("Move assignment moves data from x to z, modifying both x and z:");
    std::println("x = {}", x);
    std::println("z = {}", z);
 
    z = w; // overload (3)
    std::println("Assignment of initializer_list w to z:");
    std::println("w = {}", w);
    std::println("z = {}", z);
}

Output:

Initially:
x = {1: 1, 2: 2, 3: 3}
y = {}
z = {}
Copy assignment copies data from x to y:
x = {1: 1, 2: 2, 3: 3}
y = {1: 1, 2: 2, 3: 3}
Move assignment moves data from x to z, modifying both x and z:
x = {}
z = {1: 1, 2: 2, 3: 3}
Assignment of initializer_list w to z:
w = {4: 4, 5: 5, 6: 6, 7: 7}
z = {4: 4, 5: 5, 6: 6, 7: 7}

See also

(constructor)	constructs the flat_multimap (public member function)
replace	replaces the underlying containers (public member function)