Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
This is an older version of Boost and was released in 2017. The current version is 1.89.0.
boost::movelib::make_unique_definit
// In header: <boost/move/make_unique.hpp> template<typename T> unique_ptr< T > make_unique_definit(std::size_t n);