On Monday 2 September 2024 05:24:29 GMT-7 Tiago Freire via Std-Proposals
wrote:
I have given you a detailed explanation of the minimum set of complexity
that is required of a project to even hit such a problem. And have showed
you how that minimum set must include doing things that are considered bad
practice.
Bad practice or not, they exist.
Here's a simple one that has one such bad practice: vendoring content.
I have a project that has two vendored libraries I need, and one of them
vendors the other one to. We can call them libpng and zlib, or oneDNN and
Xbyak, or some other pair.
if, during the compilation of one of my files, both sets of headers are found
by -I options and at least one copy uses #pragma once, my build will fail.
The standard could define #pragma once to match on contents, and allow implementations to "optimize" the content comparison by using inodes/mtimes/whatever. Complex builds would ask the implementation to skip the optimization.
(well the talk about "optimization" could be left out of the standard, and implementations would choose what default they thing best)