Is it good practice to get rid of #include and only use the import keyword instead even for headers (like <span> or "Foo.h")? Are there any benefits to this? Any possible downsides? Does it add to the length of build time?

cppreference has an example in which it says this:

import <set>; // imports a synthesized header unit formed from header

What exactly does synthesized mean in this context?

CodePudding user response：

Are there any benefits to this?

Importing synthesised header units instead of including the header may satisfy a style guide that wants to use one type of directive for both modules and headers.

Any possible downsides?

It won't work in pre-C 20 code, nor compilers that haven't yet implemented importing header files. This won't matter if you also use modules, since those won't work pre-C 20 either.