NAME

std::flat_multimap::clear - std::flat_multimap::clear

Synopsis

void clear() noexcept; (since C++23)

Erases all elements from the container adaptor. After this call, size() returns
zero.

Invalidates any references, pointers, and iterators referring to contained elements.

Parameters

(none)

Return value

(none)

Complexity

Linear in the size of the container adaptor, i.e., the number of elements.

Example

// Run this code

#include <iostream>
#include <string_view>
#include <flat_map>

void print_info(std::string_view rem, const std::flat_multimap<int, char>& v)
{
std::cout << rem << "{ ";
for (const auto& [key, value] : v)
std::cout << '[' << key << "]:" << value << ' ';
std::cout << "}\n";
std::cout << "Size=" << v.size() << '\n';
}

int main()
{
std::flat_multimap<int, char> container{{1, 'x'}, {2, 'y'}, {3, 'z'}};
print_info("Before clear: ", container);
container.clear();
print_info("After clear: ", container);
}

Output:

Before clear: { [1]:x [2]:y [3]:z }
Size=3
After clear: { }
Size=0