Languages like Java or C++ have Exceptions, which are errors, that are not explicitly mentioned in the function signature. Meaning, you might need to handle an exception you didn't even know existed. And if you don't, your program will just crash when these exceptions occur.

In Rust all errors are explicitly mentioned and part of the return type. Because of this Rust has a lot of ways to quickly handle an error. One of those ways is "Trust me, bro" (or .unwrap()), which converts the combined error/success return type into just a success type, causing the program to crash if it actually was an error, restoring the more unsafe behavior of other languages.

[–] dgriffith@aussie.zone 7 points 1 month ago (4 children)

causing the program to crash if it actually was an error, restoring the more unsafe behavior of other languages.

Wellllll it's more of an abrupt exit rather than a crash, which is still better than eg. silently accessing beyond the end of an array, or ending up with a pointer to nowhere when you thought you had a sane memory reference.

[–] arendjr@programming.dev 4 points 1 month ago (3 children)

“An abrupt exit”, more commonly known as a “crash”.

If you’re going to argue that an exit through panic!() is not a crash, I will argue that your definition of a crash is just an abrupt exit initiated by the OS. In other words, there’s no meaningful distinction as the result is the same.

[–] dgriffith@aussie.zone 1 points 1 month ago* (last edited 1 month ago)

I was talking more about unwrap causing a panic rather than calling the actual panic macro directly. Rust forces the programmer to deal with bad or ambiguous results, and what that is exactly is entirely decided by the function you are calling. If a function decides to return None when (system timer mod 2 == 0), then you'd better check for None in your code. Edit: otherwise your code is ending now with a panic, as opposed to your code merrily trotting down the path of undefined behaviour and a segfault or similar later on.

Once you get to a point where we are doing the actual panic, well, that is starting to just be semantics.

load more comments (2 replies)

load more comments (3 replies)