alt Hacker News> Think of constexpr evaluation as taking place "in the compiler’s imagination."
This is a great line.
constexpr and std::execution seem like neat ideas, maybe I'll give them a shot if I build an AI harness around the compiler so it doesn't make me feel like a hopeless idiot for trying new things.
The problem isn't so much that you feel like an idiot, at least at the time, but that you may think you're a genius and yet actually what you wrote was nonsense and the C++ compiler was under no obligation to tell you about that, indeed in many cases it's forbidden from doing so.
The standard does require that if work was done at compile time the compiler is supposed to tell you if that was nonsense but (a) actually C++ is so complicated your compiler likely has many bugs in this respect and (b) you probably aren't sure the compiler did the work you expected at compile time, knowing all the excuses requires considerable expertise.