std::erase_if (std::set)
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std::set
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Erases all elements that satisfy the predicate pred from c.
Equivalent to
auto old_size = c.size(); for (auto first = c.begin(), last = c.end(); first != last;) { if (pred(*first)) first = c.erase(first); else ++first; } return old_size - c.size();
Contents |
[edit] Parameters
| c | - | container from which to erase |
| pred | - | predicate that returns true if the element should be erased |
[edit] Return value
The number of erased elements.
[edit] Complexity
Linear.
[edit] Example
Run this code
#include <iostream> #include <set> void println(auto rem, const auto& container) { std::cout << rem << '{'; for (char sep[]{0, ' ', 0}; const auto& item : container) std::cout << sep << item, *sep = ','; std::cout << "}\n"; } int main() { std::set data{3, 3, 4, 5, 6, 7, 2, 1, 0}; println("Original:\n", data); auto divisible_by_3 = [](const auto& x) { return (x % 3) == 0; }; const auto count = std::erase_if(data, divisible_by_3); println("Erase all items divisible by 3:\n", data); std::cout << count << " items erased.\n"; }
Output:
Original:
{0, 1, 2, 3, 4, 5, 6, 7}
Erase all items divisible by 3:
{1, 2, 4, 5, 7}
3 items erased.[edit] See also
| removes elements satisfying specific criteria (function template) [edit] | |
| (C++20)(C++20) |
removes elements satisfying specific criteria (algorithm function object)[edit] |
