std::flat_map<Key,T,Compare,KeyContainer,MappedContainer>::replace

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std::flat_map

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flat_map::flat_map flat_map::operator= Element access flat_map::at flat_map::operator[] Iterators flat_map::beginflat_map::cbegin flat_map::endflat_map::cend flat_map::rbeginflat_map::crbegin flat_map::rendflat_map::crend Lookup flat_map::count flat_map::find flat_map::contains flat_map::equal_range    flat_map::lower_bound flat_map::upper_bound Capacity flat_map::size flat_map::max_size flat_map::empty Modifiers flat_map::clear flat_map::erase flat_map::swap flat_map::emplace flat_map::extract flat_map::replace flat_map::insert flat_map::insert_range flat_map::insert_or_assign flat_map::emplace_hint flat_map::try_emplace Observers flat_map::key_comp flat_map::keys flat_map::value_comp flat_map::values

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

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Deduction guides

 

void replace( key_container_type&& key_cont, mapped_container_type&& mapped_cont );		(since C++23)

Replaces the underlying containers c. Equivalent to:

c.keys = std::move(key_cont);
c.values = std::move(mapped_cont);

The following conditions must be met:

• The expression key_cont.size() == mapped_cont.size() is true,
• The elements of key_cont are sorted with respect to compare, and
• key_cont does not contain equal elements.

  Otherwise, the behavior is undefined.

Parameters

keys_cont	-	a sorted keys container of type KeyContainer, the contents of which will be moved into *this
mapped_cont	-	a container of mapped values of type MappedContainer, the contents of which will be moved into *this

Return value

(none)

Complexity

Equals to complexity of std::move applied to adapted containers.

Example

Run this code

#include <algorithm>
#include <cassert>
#include <flat_map>
#include <print>
#include <vector>

int main()
{
    std::vector<int> keys{1, 2, 3};
    assert(std::ranges::is_sorted(keys));
    std::vector<double> values{2.2, 3.3, 1.1};
    assert(keys.size() == values.size());

    std::flat_map<int, double> map;
    assert(map.empty());

    map.replace(keys, values);
    assert(map.size() == 3);
    assert(map.keys() == 3);
    assert(map.values() == 3);
    assert(keys.empty());
    assert(values.empty());

    std::println("{}", map);
}

Output:

{1: 2.2, 2: 3.3, 3: 1.1}

See also

extract

extracts the underlying containers (public member function)