Re: [boost] A proposal for a modern build-system

Alright, though in the future you may want to ask clearer questions ("it" can be notoriously ambiguous).

Sorry for the confusion. I don't believe header units

are used in production by anyone except maybe in some controlled, "we pre-compile all header units before our project" cases (I believe Microsoft does something like this in their internal projects).

I compiled SFML with C++20 header-units with little to no changes in the SFML codebase. The clean build of drop-in configuration was 16s on my system compared to conventional 20s. Can build2 support such usage at such a scale? If not then I feel that my build-system has a plus point in module support. I would also like to see the syntax for such an example to do a comparison as I feel that C++ is a better choice (but that is rather subjective). I have best wishes for your project. But I am a bit opinionated about build-systems. On Fri, Mar 22, 2024 at 8:38 PM Boris Kolpackov wrote:

Hassan Sajjad writes:

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I will assume your questions refer to build2 in general rather than to its header units support specifically (which is not very usable at the moment due to compiler deficiencies).

No. my comment was in header-units and modules support context.

Alright, though in the future you may want to ask clearer questions ("it" can be notoriously ambiguous).

To briefly answer your actual question, I don't believe header units are used in production by anyone except maybe in some controlled, "we pre-compile all header units before our project" cases (I believe Microsoft does something like this in their internal projects). The reason being compiler deficiencies (lack of build system support in Clang and MSVC, and general bugginess of modules support in GCC, though I saw a lot of related bugs being fixed for GCC 14 so things might be changing).

For named modules, yes, they are being used (including with support for `import std;`). I have tried this on async_simple library:

https://github.com/boris-kolpackov/async_simple/tree/CXX20Modules-build2/asy...

And I know of a few build2 users who are using named modules in their greenfield projects.