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 1.91.0.
typedef /*user-defined*/ scalar_type;
This is the member type that user-defined (partial) specializations of the mat_traits template define the scalar type of a matrix type. Valid scalar types are value types that satisfy the scalar requirements.