std::basic_string<CharT,Traits,Allocator>::capacity
< cpp | string | basic string
size_type capacity() const; |
(C++11 前) | |
size_type capacity() const noexcept; |
(C++11 起) (C++20 前) |
|
constexpr size_type capacity() const noexcept; |
(C++20 起) | |
返回当前已为字符串分配空间的字符数。
参数
(无)
返回值
当前分配的存储容量
复杂度
常数
示例
运行此代码
#include <iostream> #include <string> void show_capacity(std::string const& s) { std::cout << "'" << s << "' has capacity " << s.capacity() << ".\n"; } int main() { std::string s{"Exemplar"}; show_capacity(s); s += " is an example string."; show_capacity(s); }
可能的输出:
'Exemplar' has capacity 15. 'Exemplar is an example string.' has capacity 31.
参阅
返回字符数 (公开成员函数) | |
保留存储 (公开成员函数) |