```
import Base.+
type numerr
num
err
end
+(a::numerr, b::numerr) = numerr(a.num + b.num, sqrt(a.err^2 + b.err^2));
+(a::Any, b::numerr) = numerr(a + b.num, b.err);
+(a::numerr, b::Any) = numerr(a.num + b, a.err);
x = numerr(10, 1);
y = numerr(20, 2);
println(x+y)
println(2+x)
println(y+2)
```
On Friday, April 1, 2016 at 4:51:53 PM UTC+2, Gerson J. Ferreira wrote:
>
> I'm trying to overload simple math operators to try a code for error
> propagation, but I'm getting a warning. Here's a short code that already
> shows the warning message:
>
> type numerr
> num
> err
> end
>
> +(a::numerr, b::numerr) = numerr(a.num + b.num, sqrt(a.err^2 + b.err^2));
> +(a::Any, b::numerr) = numerr(a + b.num, b.err);
> +(a::numerr, b::Any) = numerr(a.num + b, a.err);
>
> x = numerr(10, 1);
> y = numerr(20, 2);
>
> println(x+y)
> println(2+x)
> println(y+2)
>
> I didn't see much about operator overloading in Julia's manual. I would
> really appreciate if someone could point me in the right direction.
>
> The code above returns this warning in Julia 0.4.2:
>
> _ _ _(_)_ | A fresh approach to technical computing
> (_) | (_) (_) | Documentation: http://docs.julialang.org
> _ _ _| |_ __ _ | Type "?help" for help.
> | | | | | | |/ _` | |
> | | |_| | | | (_| | | Version 0.4.2 (2015-12-06 21:47 UTC)
> _/ |\__'_|_|_|\__'_| | Official http://julialang.org release
> |__/ | x86_64-linux-gnu
>
> julia> include("overload.jl")
> WARNING: module Main should explicitly import + from Base
> numerr(30,2.23606797749979)
> numerr(12,1)
> numerr(22,2)
>
>
>
