ms_traits Interface

# `ms_traits` Interface

Traits of a container based on its mapping semantics.

1. `ms_trait.hpp`
2. Public Types and Constants:
   1. Container attribues.

## Container attribues.

Type | Definition | Description
    has_data
    True only if the container is not a "set" type.
| Data indicator.
    has_compound_data
    True only if the container is not a "set" type or "map" type.
| Compound-data indicator.
    mapping_level
    The number of mapping-levels the container supports (1 for "set" types or "map" types).
| Mapping-level indicator.