std::experimental::erase_if (std::map)
来自 cppreference.cn
< cpp | experimental
| 定义于头文件 <experimental/map> |
||
| template< class Key, class T, class Compare, class Alloc, class Pred > void erase_if( std::map<Key, T, Compare, Alloc>& c, Pred pred ); |
(库基础 TS v2) | |
从容器中移除所有满足谓词 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; }
目录 |
[edit] 参数
| c | - | 要从中移除元素的容器 |
| pred | - | 确定应移除哪些元素的谓词 |
[edit] 复杂度
线性复杂度。
[edit] 示例
运行此代码
#include <experimental/map> #include <iostream> template<typename Os, typename Container> inline Os& operator<<(Os& os, Container const& cont) { os << '{'; for (const auto& item : cont) os << '{' << item.first << ", " << item.second << '}'; return os << '}'; } int main() { std::map<int, char> data{{1, 'a'},{2, 'b'},{3, 'c'},{4, 'd'}, {5, 'e'},{4, 'f'},{5, 'g'},{5, 'g'}}; std::cout << "Original:\n" << data << '\n'; std::experimental::erase_if(data, [](const auto& item) { return (item.first & 1) == 1; }); std::cout << "Erase items with odd keys:\n" << data << '\n'; }
输出
Original:
{{1, a}{2, b}{3, c}{4, d}{5, e}}
Erase items with odd keys:
{{2, b}{4, d}}[edit] 参见
| 移除满足特定条件的元素 (函数模板) |
