std::unique_ptr<T,Deleter>::operator<< (3) - Linux Manuals

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


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


template <class CharT, class Traits, class Y, class D>
std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, (since C++20)
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 only participates in overload resolution if os << p.get() is a valid expression.


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

Return value



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.


// Run this code

  #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:


See also

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