4 ms·

Why would you prefer to preincrement an integer? Too much time around C++ iterators?

• saurik 2y ago
  I mean, why would you ever prefer to post-increment an integer whose prior value you didn't need? Not enough time studying iterators to make that distinction obvious, perhaps? Regardless, the context here is that we should stop relying so much on the compiler to paper over differences in code that don't by the user anything except a form of quaint familiarity with old code: the i++ relies on the optimizer knowing it doesn't have to keep the prior value, while ++i doesn't, and yet somehow I guess you are enamored with i++ despite it being exactly the same characters to type, merely in a different order. Stop using int, stop using post-increment, and sure: maybe even stop using < when you semantically want != (though I explicitly didn't go there because that isn't--as far as I know--going to affect the performance with a dumber compiler).
  • JonChesterfield 2y ago
    Pattern matching is a big thing in programming. Not in C++, as ++i executes arbitrary code found an unbounded distance from the programmer (so ++i vs i++ might be a very important distinction) but in other languages it helps a lot. for (int i=0, j=0; i < N && j < M; i+=2, j++) i++ looks like i+=1 so fits better in loops iterating over multiple things. Also that int says "these values don't overflow" very concisely and the more modern cleverer C++ using iterator facades probably fails to communicate that idea to anyone. edit: amused to note on checking for typos that I wrote that with < instead of != which violates your other recommendation, which is one I'm in favour of in theory but apparently don't write out by default.