On Sat, Feb 14, 2015 at 6:03 AM, Xinchen Hui <larue...@php.net> wrote:
> Hey: > > > > On Sat, Feb 14, 2015 at 11:18 AM, Andrea Faulds <a...@ajf.me> wrote: > > Hi everyone, > > > > I’ve written a small RFC and patch to add a “void” return type: > > > > https://wiki.php.net/rfc/void_return_type > > > > Please have a read over it. I think this would be a simple, yet useful > addition. > be honest, I think it's only part of the idea is implemented. > > which make it useless. > > in PHP, even if you don't return anything, NULL is returned implicitly. > > even if a function is declared return nothing(void). > > like: > > function a() : void {}; > > following codes still works: > > $b = a(); > > so, if you want a void return type, and if you want it to be a useful > feature.. > > above expr should be invalid with an error " a() return nothing" > > so, I am -1 on this in complete RFC > Hi Xinchen! While doing something like $b = a() where a() is a void function does not make sense usually (and e.g. C will generate a warning/error for this) in PHP there are some cases where you would want to use the return value of a void function. Namely those are cases where you aren't calling a specific function, but a callback that can return anything instead. E.g. consider something like a partial application helper: function bind($fn, ...$bindArgs) { return function(...$args) use($fn) { return $fn(...$bindArgs, ...$args); }; } Right now this would work no matter how $fn is declared. However if you disallow using the return value of void functions, you'd have to create an extra bindVoid() function which does exactly the same thing, just without the "return". As such I don't think we can reasonably forbid using the return value of a void function. The utility of the "void" return type in PHP would be self-documenting function signatures. An IDE (or other static analyzer) would of course detect cases where the return value of a void function is used. Nikita
