C++ named requirements: ScalarType
From cppreference.com
                    
                                        
                    
                    
                                                            
                    Note: the standard doesn't define a named requirement with this name. This is a type category defined by the core language. It is included here as a named requirement only for consistency.
Requirements
The following types are collectively called scalar types:
| (since C++11) | 
- cv-qualified versions of these types
 
See also
|    (C++11)  | 
   checks if a type is a scalar type   (class template)  |