std::basic_string<CharT,Traits,Allocator>::shrink_to_fit

`void shrink_to_fit();`		( C++20)
`constexpr void shrink_to_fit();`		( C++20)

.

capacity() size(). , .

( ) , , .

()

( )	( C++17)
.	( C++17)

libstdc++, shrink_to_fit() C++98.

#include <iostream>
#include <string>

int main()
{
    std::string s;
    std::cout << " std::string  " << sizeof s << " \n"
        << "     " << s.capacity() 
        << "    " << s.size() << '\n';
    
    for (int i = 0; i < 42; i++)
        s.append(" 42 ");
    std::cout << "  42   " << s.capacity() 
        << "    " << s.size() << '\n';
    
    s.clear();
    std::cout << "  clear()  " << s.capacity() 
        << "    " << s.size() << '\n';
    
    s.shrink_to_fit();
    std::cout << "  shrink_to_fit()  " << s.capacity() 
        << "    " << s.size() << '\n';
}

:

GCC output:
 std::string  32 
     15    0
  42   240    168
  clear()  240    0
  shrink_to_fit()  15    0

clang output (with -stdlib=libc++):
 std::string  24 
     22    0
  42   191    168
  clear()  191    0
  shrink_to_fit()  22    0

C++:


LWG 755	C++98	`std::string`

sizelength	(public -) []
capacity	, (public -) []
resize	(public -) []







(C++20)

(C++20)
(C++11)





(C++20)


/

(C++11)
(C++11)
(C++11)
(C++17)

cppreference.com

std::basic_string<CharT,Traits,Allocator>::shrink_to_fit