yeah! you can get an enormous amount of metaprogramming mileage out of c++ templates. i think the pattern-matching paradigm embodied by sfinae is maybe a better fit for, effectively, user-defined language extensions, than the more straightforward imperative approach lisp uses by default. but c++ templates are unnecessarily hard to debug i think, for reasons that aren't inherent to the pattern-matching paradigm

i didn't get c to compile three orders of magnitude faster, just 44×–56× faster (4400% to 5500%). sorry to be confusing!

i've certainly experienced the temptation to roll my own matrix library more than once, and i'll definitely have to do it at least once for the zorzpad. i may do something this week in order to understand the simplex method better; my operations research class was years ago, and i've forgotten how it works, probably because i never implemented it in software, just worked through examples by hand and on the chalkboard

Honestly, it was a school project, i had time and my final internship was month away, so i took the time to do it. Barely finished in time and it was quite lousy, but i was proud of it. It was my peak "Dunning-Kruger", because i was probably the most mathematically-inclined of all my classmates, and thought i was really clever.

Funny stuff, during my final internship i made a heavy use of scikit-image, learned about openBlas and unterstood how much better low-level libraries were for matrix computation, and how far away my own library was. And at my next job i was setting up our PaaS VMs with a lot of stuff, including TitanX with Cuda and pytorch, informed myself on the tools i was installing (i did set up tutorials in notebooks for an easy launch), and then understood i was years behind and way less informed than i thought i was. I think i learned about HN around that time.