4 Specification [spec]

4.1 External [spec.ext]

The specification of the mp-units library subsumes N4971, [description], N4971, [requirements], N4971, [concepts.equality], and SD-8, all assumingly amended for the context of this library.
[Note 1: 
This means that, non exhaustively,
  • ​::​mp_units2 is a reserved namespace, and
  • std​::​vector<mp_units​::​type> is a program-defined specialization and a library-defined specialization from the point of view of the C++ standard library and the mp-units library, respectively.
— end note]
The mp-units library is not part of the C++ implementation.