# Type Traits: Categories and Transformations

This lesson is an extension of the previous lesson where we'll study categories and transformations of type traits.

## Primary type categories #

C++ has 14 primary type categories. They are complete and orthogonal, meaning that each type is exactly a member of one type category. The check for the type categories is independent of the type qualifiers `const`

or `volatile`

.

The 14 primary type categories are as follows:

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