C++ Data Type constexpr

Description

Click the following links for the tutorial for Data Type and constexpr.

1. The constexpr Keyword
2. Create a constexpr function.
3. Create a class with a constexpr constructor.
4. C++14 constexpr function can limit the maximum size of an array.
5. Use Compile Time Constants with constexpr to guarantee that an expression can be evaluated at compile time.