Type traits
When doing template metaprogramming, you may often find yourself in situations where you need information about the types you are dealing with at compile time. When writing regular (non-generic) C++ code, we work with concrete types that we have complete knowledge about, but this is not the case when writing a template; the concrete types are not determined until a template is being instantiated by the compiler. Type traits let us extract information about the types our templates are dealing with in order to generate efficient and correct C++ code.
In order to extract information about template types, the standard library provides a type traits library, which is available in the <type_traits> header. All type traits are evaluated at compile time.
Type trait categories
There are two categories of type traits:
- Type traits that return information about a type as a boolean or an integer value.
- Type traits that return a new type. These type...
