W3cubDocs

/C++

std::unique_ptr::operator<<

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);
(since C++20)

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

Equivalent to os << p.get().

This overload only participates in overload resolution 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 output:

0x6d9028
0x6d9028

See also

returns a pointer to the managed object
(public member function)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/memory/unique_ptr/operator_ltlt