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Comment by MauranKilom | Hacker News Reader

> I can write a c++ compiler in a few months.

Not that it substantially distracts from your point, but I strongly doubt this. Or did you mean a heavily restricted subset of C++? A C++ front end alone is so complex to build that these guys make a living off of licensing their front end code: https://www.edg.com/

(Fun fact: Microsoft rebuilt IntelliSense for C++ on the EDG front end. Yes, that Microsoft with the MSVC compiler. See https://devblogs.microsoft.com/cppblog/rebuilding-intellisen... and https://old.reddit.com/r/cpp/comments/bdt8ep/does_msvc_still...)

Even without compatibility cruft, you're looking at multiple 100k LOC if their code base is anything to go by. That's man-years, not man-months...

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Edg is writing a good front end. With good error handling and all of the other things that make a commercial program a few hundred times harder than a quick prototype. I'd be writing a brute force front end that is slow, and goes straight to assembly. If there is a syntax error I'll handle it by crashing. When you create a variable is used twice in a row I'll store the intermediate value back into memory and reload it back into my register.

There have been write a c++ compiler classes that did it in a semester. I think they also do the standard library. (but that might be a year long course)

I'm still awfully skeptical that you can get even close to understanding all the template, lookup, lifetime, lambda, exception and initialization rules in a semester (I assume that CS students are almost never this deep into C++ at that point). Not to speak of actually implementing all of it.

I'd be curious where these classes draw the line. Do you happen to have a syllabus or so? I don't doubt you can implement a meaningful portion of C++ in a semester, but converting 500 pages of standardese into code within as many hours seems like an impossible goal for a class to me.

http://www.cppgm.org/ was a sort of experiment called "C++ Grand Master Certification." It seems to have died out, but the goal was to produce a self-hosted C++-11 compiler and standard library implementation. It took about a year to go from nothing to code generation in 9 programming assignments (I think I completed the first 6 before I got too busy to continue).

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