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 participates in overload resolution only 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 |
os
.
If std::unique_ptr<Y, D>::pointer
is a pointer to a character type (e.g., when Y
is 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.
#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
returns a pointer to the managed object (public member function) |
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