std::experi...ordered_set)(3)

💖 NAME

std::experimental::erase_if(std::unordered_set) — bestie, this is the std::experimental::erase_if(std::unordered_set) page, no cap. It lives in the C++ Standard Library, and the page title vibe is std::experi...ordered_set)(3).

✨ Synopsis

Defined in header <experimental/unordered_set>.

This one is tagged library fundamentals TS v2, iykyk:

template< class Key, class Hash, class KeyEqual, class Alloc, class Pred >
void erase_if( std::unordered_set<Key, Hash, KeyEqual, Alloc>& c, Pred pred );

It erases all elements that satisfy the predicate pred from the container. Equivalent to:

for (auto i = c.begin(), last = c.end(); i != last;)
{
    if (pred(*i))
        i = c.erase(i);
    else
        ++i;
}

🎀 Parameters

• c — container from which to erase. That's the main character container, periodt.
• pred — predicate that determines which elements should be erased. It's giving "vibe check, but for elements."

🌸 Complexity

Linear. Literally linear, bestie. That's the whole complexity tea.

🦋 Example

// Run this code

#include <experimental/unordered_set>
#include <iostream>

template<typename Os, typename Container>
inline Os& operator<<(Os& os, Container const& container)
{
    os << "{ ";
    for (const auto& item : container)
        os << item << ' ';
    return os << '}';
}

int main()
{
    std::unordered_set<int> data{3, 3, 4, 5, 5, 6, 6, 7, 2, 1, 0};
    std::cout << "Original:\n" << data << '\n';
    auto divisible_by_3 = [](auto const& x) { return (x % 3) == 0; };
    std::experimental::erase_if(data, divisible_by_3);
    std::cout << "Erase all items divisible by 3:\n" << data << '\n';
}

Possible output:

Original:
{ 0 1 2 7 6 5 4 3 }
Erase all items divisible by 3:
{ 1 2 7 5 4 }

💅 See also

• remove — removes elements satisfying specific criteria
• remove_if — (function template)

🌈 Category

• Noindexed pages

okay so that's the page, bestie 🫶 — source/version/date energy: http://cppreference.com, 2024.06.10. Obsessed with this footer moment, fr fr 💜