alt Hacker NewsThere was in visual studio which has had it other than minor details.the real problem is tools are needed to make modules work and those needed a lot of work. The work was already partially there because it's the same work that Fortran needs which tools supported but there were just enough details different to be annoying. Fortran modules were something that were always an afterthought and when tools started realizing that this is going to be a big deal, they decided they had to do it right, which took a lot of time too.
Maybe you forget Hacker News of 10 years ago, but in 2015-2016, everyone was complaining C++ doesn't have modules and how awful it must be because they're not modules. Now that C++ has modules, they're complaining about how it has modules.
I don't remember because I wasn't there :)
People are not complaining about the fact that C++ has modules, but about their usability and effectiveness. The compile time benefits seem modest and I have seen reports that it breaks Intellisense. (Maybe that's not true anymore?)
As Vittorio said, if it takes compiler vendors so long to implement them properly, maybe the design wasn't that good after all?
My point was: if you add such a big feature, shouldn't the standard require a sufficiently complete implementation? Otherwise, how can they assess whether the proposal actually works in practice and lives up to its promises?