Does that mean that, in a modules world, for the compiler to be able to optimize away function calls we have to annotate them as inline even if they are defined in-class? To some degree. Inlining is an “as if” optimization, and inlining can happen even between translation units if the compiler is clever enough. … Read more
As of this commit, Clang has experimental support for the Modules TS. Let’s take the same example files (with a small change) as in the VS blog post about experimental module support. First, define the module interface file. By default, Clang recognizes files with cppm extension (and some others) as C++ module interface files. // … Read more
Experimental Modules Support This reflects the status as of CMake 3.26. I will keep updating this answer as the situation changes. Important: CMake’s support for C++20 modules is currently functional, but still experimental. Things may work in some cases but break in others. Expect bugs and breaking changes between versions! Prerequisites Proper integration currently only … Read more
Currently C++ implementations really only have two “things” that correspond to code: source code that we human write and edit, and assembly, which the compiler spits out based on source. Because C++ templates are “reified”, separate assembly is spit out for each template instantiation. For that reason, no assembly can be produced where the templates … Read more
There are already two compilers that support C++ modules clang: http://clang.llvm.org/docs/Modules.html MS VS 2015: http://blogs.msdn.com/b/vcblog/archive/2015/12/03/c-modules-in-vs-2015-update-1.aspx The Microsoft approach appears to be the one gaining the most traction, mainly because Microsoft are throwing a lot more resources at their implementation than any of the clang folk currently. See https://llvm.org/bugs/buglist.cgi?list_id=100798&query_format=advanced&component=Modules&product=clang for what I mean, there are some … Read more