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

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

Return value

(none)

Complexity

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

Example

#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);
}

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

See also