std::basic_string::shrink_to_fit
void shrink_to_fit(); | | (since C++11) |
|---|
请求清除未使用的容量。
这是一个不具有约束力的请求来减少capacity()到size().这取决于请求是否得到满足的实现。
如果发生重新分配，则所有指针、引用和迭代器都将失效。
参数
%280%29
返回值
%280%29
复杂性
常量。
例
二次
#include <iostream>
#include <string>
int main()
{
std::string s;
std::cout << "Default-constructed capacity is " << s.capacity() << '\n';
s.resize(100);
std::cout << "Capacity of a 100-element string is " << s.capacity() << '\n';
s.clear();
std::cout << "Capacity after clear() is " << s.capacity() << '\n';
s.shrink_to_fit();
std::cout << "Capacity after shrink_to_fit() is " << s.capacity() << '\n';
}二次
产出：
二次
Default-constructed capacity is 0
Capacity of a 100-element string is 100
Capacity after clear() is 100
Capacity after shrink_to_fit() is 0二次
另见
sizelength | returns the number of characters (public member function) |
|---|---|
capacity | returns the number of characters that can be held in currently allocated storage (public member function) |
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