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

Solicita la eliminación de capacidad no utilizada.

Es una solicitud no vinculante para reducir capacity() a size() . Depende de la implementación si la solicitud es cumplida.

Si (y solo si) tiene lugar una relocalización, todos los punteros, referencias e iteradores quedan invalidados.

Complejidad

Lineal en el tamaño de la cadena.

Notas

En libstdc++, shrink_to_fit() está no disponible en modo C++98.

Ejemplo

#include <iostream>
#include <string>
int main()
{
    std::string s;
    std::cout << "Size of std::string is " << sizeof s << " bytes\n"
        << "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 42 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';
}

Salida GCC:
Size of std::string is 32 bytes
Default-constructed capacity is 15 and size 0
Capacity after 42 appends is 240 and size 168
Capacity after clear() is 240 and size 0
Capacity after shrink_to_fit() is 15 and size 0
Salida clang (con -stdlib=libc++):
Size of std::string is 24 bytes
Default-constructed capacity is 22 and size is 0
Capacity after 42 appends is 191 and size is 168
Capacity after clear() is 191 and size is 0
Capacity after shrink_to_fit() is 22 and size is 0

Informes de defectos

Los siguientes informes de defectos que modifican el comportamiento se aplicaron retroactivamente a los estándares de C++ publicados anteriormente.

Véase también