What are the limitations of constexpr in C++17?

What are the limitations of constexpr in C++17?

In C++17, constexpr functions can have more complex bodies, but there are still limitations. For instance, you can't use dynamic memory allocation or certain types of I/O operations within a constexpr function.

Can you give me an example of a limitation?

Sure! One limitation is that you cannot use std::vector or other dynamic containers in a constexpr context, as they require dynamic memory allocation.

What about constexpr variables? Are there any restrictions?

Yes, constexpr variables must be initialized with a constant expression. You can't assign them values at runtime, and they must be defined at compile time.

How does this compare to C++14?

C++17 allows more complex constexpr functions compared to C++14, but the fundamental limitations regarding dynamic memory and certain operations remain.