std::experimental::erase_if (std::unordered_set)
From cppreference.com
< cpp | experimental
| Defined in header <experimental/unordered_set>
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| template< class Key, class Hash, class KeyEqual, class Alloc, class Pred > void erase_if( std::unordered_set<Key, Hash, KeyEqual, Alloc>& c, Pred pred ); |
(library fundamentals TS v2) | |
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 |
| pred | - | predicate that determines which elements should be erased |
Complexity
Linear.
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
| removes elements satisfying specific criteria (function template) |