What are the differences in how compilers handle constexpr in C++?

What are the differences in how compilers handle constexpr in C++?

Different compilers may have varying levels of support for constexpr, especially in older versions. For instance, GCC and Clang have robust support for constexpr, allowing complex expressions, while MSVC may have limitations in certain scenarios.

Can you give examples of those limitations in MSVC?

Sure! In MSVC, earlier versions had restrictions on using constexpr with certain types of expressions, like those involving dynamic memory allocation or certain standard library functions. However, newer versions have improved this support.

How does constexpr affect performance in C++?

Using constexpr can improve performance by allowing computations to be done at compile time, reducing runtime overhead. This can lead to faster execution and smaller binary sizes.

Are there any best practices for using constexpr?

Yes, it's best to use constexpr for functions that can be evaluated at compile time, avoid side effects, and ensure that the function's parameters are also constexpr-compatible.