std::basic_string<CharT,Traits,Allocator>::shrink_to_fit
来自cppreference.com
< cpp | string | basic string
| void shrink_to_fit(); |
(C++11 起) (C++20 前) |
|
| constexpr void shrink_to_fit(); |
(C++20 起) | |
请求移除未使用的容量。
这是减少 capacity() 到 size() 的非强制请求。是否满足请求取依赖于实现。
若（且唯若）发生重分配，则非法化所有指针、引用和迭代器。
参数
（无）
返回值
（无）
复杂度
|
（未指明） |
(C++17 前) |
|
与 string 大小成线性 |
(C++17 起) |
示例
运行此代码
#include <iostream> #include <string> int main() { std::string s; std::cout << "Default-constructed capacity is " << s.capacity() << " and size is " << s.size() << '\n'; for (int i=0; i<42; i++) s.append(" 42 "); std::cout << "Capacity after a couple of appends is " << s.capacity() << " and size is " << s.size() << '\n'; s.clear(); std::cout << "Capacity after clear() is " << s.capacity() << " and size is " << s.size() << '\n'; s.shrink_to_fit(); std::cout << "Capacity after shrink_to_fit() is " << s.capacity() << " and size is " << s.size() << '\n'; }
可能的输出：
Default-constructed capacity is 15 and size 0 Capacity after a couple of appends is 240 and size 168 Capacity after clear() is 240 and size 0 Capacity after shrink_to_fit() is 15 and size 0
参阅
| 返回字符数 (公开成员函数) | |
| 返回当前对象分配的存储空间能保存的字符数量 (公开成员函数) |
