Re: [rust-dev] About const

[Philippe Daouadi <blastrock0@free.fr>]

[-- Attachment #1: Type: text/plain, Size: 1612 bytes --]

If you want a generic pi, you should use the one in the Float trait

If you have
let x : f64 = ...;
x * Float::pi() will resolve to f64 pi

Philippe

On 01/04/2015 05:21 PM, Manish Goregaokar wrote:
> We have two types of floats, there is a Pi of both precision levels. I 
> don't think it's anything more than that. You should be able to cast 
> between the two, but that's it I guess. Rust tries to give explicit 
> control over such things.
>
> There is a Float trait (might have been renamed) if you want to use 
> generics.
>
> -Manish Goregaokar
>
> On Sun, Jan 4, 2015 at 3:07 PM, Pim Schellart <p.schellart@gmail.com 
> <mailto:p.schellart@gmail.com>> wrote:
>
>     Dear Rust Developers,
>
>     here is another ignorant question so feel free to ignore.
>     When reading the guide I came across "std::f64::consts::PI” for
>     pi. Now I was wondering why there are separate constants defined
>     for 32 and 64 bit floats and how this will work with generics. Do
>     you always have to define two functions to work on f32 and f64 or
>     is std::f64::consts::PI cast down to f32 in an equation with 32
>     bit variables? Is there also a general `typeless’ PI (or other
>     fundamental constants), as in Go for example?
>
>     Kind Regards,
>
>     Pim
>     _______________________________________________
>     Rust-dev mailing list
>     Rust-dev@mozilla.org <mailto:Rust-dev@mozilla.org>
>     https://mail.mozilla.org/listinfo/rust-dev
>
>
>
>
> _______________________________________________
> Rust-dev mailing list
> Rust-dev@mozilla.org
> https://mail.mozilla.org/listinfo/rust-dev


[-- Attachment #2: Type: text/html, Size: 3292 bytes --]