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 2013. The current version is 1.89.0.
All the value based traits in this library conform to MPL's requirements for an Integral Constant type: that includes a number of rather intrusive workarounds for broken compilers.
Purely as an implementation detail, this means that true_type
inherits from boost::mpl::true_,
false_type
inherits from boost::mpl::false_,
and integral_constant<T,
v>
inherits from boost::mpl::integral_c<T,v>
(provided T is not bool)