[phire]

Short circuiting introduces conditional branching. If you call a function on the right hand side of a || or && it might or might not be executed depending on the value of the left hand side.

Until this version of rust, all conditional branches were banned from const functions.

I guess to keep things simple they just banned any feature that might cause branching.

[marton78]

Why is branching a problem? Since `if` is now enabled in a const fn, it's trivial to rewrite && with & and if.

[kibwen]

`if` wasn't enabled before, so `&&` wasn't enabled. Now that `if` is enabled, `&&` now works too.

[marricks]

Ahh that makes a lot of sense, if you're going to have a compiler insert the result of a function having conditional branching seems a bit gnarly I guess?

[kibwen]

For the history of this feature request, see https://github.com/rust-lang/rust/issues/29608 as a starting point.

[Filligree]

It's conditional based on what's ultimately constant data, so you end up with predictable output regardless.