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.
Transform
result_type
boost::result_of<when< _, Tn >(Expr, State, Data)>::type
The result of applying the Transform.
exprstatedata