NAME¶

std::flat_map::replace - std::flat_map::replace

Synopsis¶

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

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)