Re: RFC: Marking return values as important (#[\NoDiscard])

On Wed, Jan 29, 2025, at 20:50, Tim Düsterhus wrote: > Hi > > On 1/29/25 20:31, Rob Landers wrote: > > This looks promising! > > > > Why do we need the (void) cast? Wouldn't "@" work and avoid a BC issue? > > The @ operator also suppresses any other warning or notice > within the > call chain. That is likely undesirable because it might hide issues one > is interested in. See this example (https://3v4l.org/NDtR7): > > <?php > function inner() { > var_dump($undefined); > } > > function outer() { > inner(); > } > > outer(); > outer(); > @outer(); > > The (void) cast makes the intent of not being interested in the > return > value clear. In C casting to (void) is an established pattern > of > "using" a value that the compiler would otherwise consider unused. > Likewise will the void operator suppress the TypeScript-ESLint > warning > of not using returned Promise: > > https://typescript-eslint.io/rules/no-floating-promises/#ignorevoid > > Best regards > Tim Düsterhus > Hi Tim, I understand what you are saying, but I can also just remove the warning via: $_ = outer; Which, to me, is clearer on the intent than (void)outer(); It also happens to make the diffs more natural looking when and if the return value gets used during a code review. I'll also note that having (void) doesn't preclude me from using $_ either. I was mostly just curious as to the reasoning; I don't like it, but it makes sense. Best of luck! — Rob