std::unique_ptr<T,Deleter>::operator<<

Declaration

Since C++20

template< class CharT, class Traits, class Y, class D >
std::basic_ostream<CharT, Traits>& operator<<( std::basic_ostream<CharT, Traits>& os,
                                               const std::unique_ptr<Y, D>& p );

Inserts the value of the pointer managed by p into the output stream os.

Equivalent to os << p.get().

This overload participates in overload resolution only if os << p.get() is a valid expression.

Parameters

os - a std::basic_ostream to insert p into p - the pointer to be inserted into os

Return value

os

Notes

If std::unique_ptr<Y, D>::pointer is a pointer to a character type (e.g., when Y is char or char[] or CharT), this may end up calling the overloads of operator<< for null-terminated character strings (causing undefined behavior if the pointer does not in fact point to such a string), rather than the overload for printing the value of the pointer itself.

Example

#include <iostream>
#include <memory>
 
class Foo {};
 
int main()
{
    auto p = std::make_unique<Foo>();
    std::cout 
        << p << '\n';
    std::cout 
        << p.get() << '\n';
}

Possible Result

0x6d9028
0x6d9028