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
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
boost::type_erasure::_self — The default placeholder.
// In header: <boost/type_erasure/placeholder.hpp> struct _self : public boost::type_erasure::placeholder { };
_self is the default placeholder used by any. It should be used as a default by most concepts, so using concepts with no explicit arguments will "just work" as much as possible.