I've been anxiously awaiting modules and concepts. Both are incredibly important to reduce developer burden and improve the development experience.
Modules: While it is important to be able to fine-tune linking and compilation in some settings, in most, and especially for beginners, this should be handled by the compiler. Especially when compared to other modern languages, C++ is much more complex to understand the toolchain and what's going on under the covers with the dichotomy of compilation and linking. Header files were a hack that have been around for too long, and there needs to be less separation between the interface and actual binary code when compiling. This is a headache both for novices and the experienced.
Concepts: The missing link for templates. Besides removing some of the roundabout-ism of SFINAE by providing compile-time verifiable interfaces, I think the biggest benefit of concepts will be the error messages. Right now, the state of errors in heavily templated code is abysmal, and this translates to a lot of wasted time for developers. Concepts should allow the errors to indicate exactly what's wrong.
I can't wait to be able to use these in public code. Some compilers support concepts with a flag already (and GCC 10 has it without the special flag), though none support modules yet...
Modules: While it is important to be able to fine-tune linking and compilation in some settings, in most, and especially for beginners, this should be handled by the compiler. Especially when compared to other modern languages, C++ is much more complex to understand the toolchain and what's going on under the covers with the dichotomy of compilation and linking. Header files were a hack that have been around for too long, and there needs to be less separation between the interface and actual binary code when compiling. This is a headache both for novices and the experienced.
Concepts: The missing link for templates. Besides removing some of the roundabout-ism of SFINAE by providing compile-time verifiable interfaces, I think the biggest benefit of concepts will be the error messages. Right now, the state of errors in heavily templated code is abysmal, and this translates to a lot of wasted time for developers. Concepts should allow the errors to indicate exactly what's wrong.
I can't wait to be able to use these in public code. Some compilers support concepts with a flag already (and GCC 10 has it without the special flag), though none support modules yet...