std::experimental::erase_if (std::unordered_set) - cppreference.com (original) (raw)
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Merged into ISO C++ The functionality described on this page was merged into the mainline ISO C++ standardas of 11/2018, see std::erase_if (since C++20) |
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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; }
[edit] Parameters
| c | - | container from which to erase |
|---|---|---|
| pred | - | predicate that determines which elements should be erased |
[edit] Complexity
Linear.
[edit] Example
#include <experimental/unordered_set> #include 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 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 }