std::flat_set<Key,Compare,KeyContainer>::clear

 

C++

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Symbols index

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Containers library

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std::flat_set

Member types

Member functions

flat_set::flat_set flat_set::operator= Iterators flat_set::beginflat_set::cbegin flat_set::endflat_set::cend flat_set::rbeginflat_set::crbegin flat_set::rendflat_set::crend Capacity flat_set::size flat_set::max_size flat_set::empty Observers flat_set::key_comp flat_set::value_comp      Modifiers flat_set::clear flat_set::insert flat_set::insert_range flat_set::emplace flat_set::emplace_hint flat_set::erase flat_set::swap flat_set::extract flat_set::replace Lookup flat_set::count flat_set::find flat_set::contains flat_set::equal_range flat_set::lower_bound flat_set::upper_bound Non-member functions operator==operator<=> swap(std::flat_set) erase_if(std::flat_set)

Helper classes

uses_allocator<std::flat_set>

Tags

sorted_unique      sorted_unique_t

Deduction guides

 

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_set>
 
void print_info(std::string_view rem, const std::flat_set<int>& v)
{
    std::cout << rem << "{ ";
    for (const auto& value : v)
        std::cout << value << ' ';
    std::cout << "}\n";
    std::cout << "Size=" << v.size() << '\n';
}
 
int main()
{
    std::flat_set<int> container{1, 2, 3};
    print_info("Before clear: ", container);
    container.clear();
    print_info("After clear: ", container);
}

Output:

Before clear: { 1 2 3 }
Size=3
After clear: { }
Size=0

See also

erase

erases elements (public member function)