An illuminating "mini-FAQ" on a very current major feature progressing in ISO C++:

Common C++ Modules TS Misconceptions

by Boris Kolpackov

From the article:

It has become fashionable to criticize C++ Modules TS. My problem with this bandwagon criticism is that at best it's based on cursory reading of the specification but more commonly on just hearing others' knee-jerk reactions. Oftentimes the criticizing post cannot even get the terminology right. So in this article I would like to refute the most common Modules TS misconceptions...

• I cannot have everything in a single file
• I cannot export macros from modules
• I cannot modularize existing code without touching it
• No build system will be able to support modules