These are chat archives for rust-lang/rust

Dec 2017
Fra ns
Dec 04 2017 09:55
Yup been like that for 2-3 days now
It’s due to missing rls-preview
Andrey Lesnikov
Dec 04 2017 10:07
@steveklabnik hi, is it ok that osx beta is still broken for zemeroth?
Dec 04 2017 12:23

I have a problem when using Derivative on structure with reference field. When this field need custom format function.

The code looks like this

struct Foo<'a> {
    ... // more fields
    events: &'a EventsLoop,

fn fmt_events_loop(events: &EventsLoop, fmt: &mut fmt::Formatter) -> fmt::Result {
    write!(fmt, "EventsLoop")

And the error:

in type `&'_derivative &'a winit::EventsLoop`, reference has a longer lifetime than the data it references
Denis Lisov
Dec 04 2017 12:33
I'd guess this can be a bug in derivative...
Steve Klabnik
Dec 04 2017 13:11
@ozkriff not sure, i didn't know beta was broken
So it seems that rust just actually can't handle composed trait objects :(
And it gives you really weird errors too
Could anyone help?
The impl's are all 'legal' to write, but apparently illegal to use. I've tried specifying coerced as &TraitA but that just makes it mad (unsized type)
Denis Lisov
Dec 04 2017 14:18
@Restioson What are you actually trying to do?
Dec 04 2017 14:18
Unfortunately, that :(
with real traits
have a CoerceToWhatever trait which returns Whatever if the type it is called on is an instance of Whatever
to let terminals remain generic but also allow access to subtrait features like colors if supported
Maybe there's a better way I haven't thought of, but ideally i dont want to just include all the methods and then just error if they arent supported...
Yavuz Günay
Dec 04 2017 14:33
is there any video editing library ?
Sherab Giovannini
Dec 04 2017 15:19
@yvz5 since anyone anwser you I would say that no <= here you have a pretty good crate classify
and there is nothing related to video/audio but bindings instead, which is an option tbh
you should have bindings to mostly all typical popular libs out there
there are bindings for gstreamer and such libs like that
Denis Lisov
Dec 04 2017 15:50
@Restioson Looks like you're trying to invent something like Any?
Karan Chaudhary
Dec 04 2017 18:45
Hi, I need to send a HTTP req where content-type provided by user. How can i check if content type is valid of not, and if valid set correct header on request using hyper?
Sherab Giovannini
Dec 04 2017 22:31 this is from reqwest, but the approach should be similar