std::experimental::erase_if (std::unordered_multiset)

来自cppreference.com

template <class Key, class Hash, class KeyEqual, class Alloc, class Pred>
void erase_if(std::unordered_multiset<Key, Hash, KeyEqual, Alloc>& c, Pred pred);
(库基础 TS v2)

从容器擦除所有满足谓词 pred 的元素。等价于

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

参数

c - 要从中擦除的容器
pred - 确定该擦除哪些元素的谓词

复杂度

线性。

示例

#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_multiset<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';
}

可能的输出:

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

参阅

移除满足特定判别标准的元素
(函数模板)