std::erase_if (std::unordered_multiset)

Defined in header `<unordered_set>`
template< class Key, class Hash, class KeyEqual, class Alloc, class Pred > void erase_if(std::unordered_multiset<Key,Hash,KeyEqual,Alloc>& c, Pred pred);	(1)	(since C++20)

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;
  }
}

c	-	container from which to erase
pred	-	predicate that returns `true` if the element should be erased

Linear.