feat: Add ToSpanTrait to Spans

[bengineer42]

Feature Request

Describe the Feature Request
Add the ToSpanTrait to Spans to enhance generics

    fn do_something_on_many<TS, T, +ToSpanTrait<TS, T>>(collection: TS){
        collection.to_span().into_iter().map(|c| c.do_something())
   }

Where do_something_on_many can take Span<T>, Array<T> or [T; N] and in some cases of [T; N] It can solve the Non zero compiler issues

Describe Preferred Solution

impl SpanToSpan<T> of ToSpanTrait<Span<T>, T> {
    #[inline]
    fn span(self: @Span<T>) -> Span<T> {
        *self
    }
}

Describe Alternatives

Related Code

Additional Context

If the feature request is approved, would you be willing to submit a PR?
(Help can be provided if you need assistance submitting a PR)

• Yes
• No

[orizi]

this sounds like something that can be solved by using IntoIterator - isn't it?

[bengineer42]

Not always, if you want to build on libraries that already have function signitures of Span, or if you want to use in types or instances where the underlying usage isnt using the IntoIterator trait.

struct MyType<T> {
    values: Span<T>,
}

#[generate_trait]
impl MyTypeImpl<T, +Drop<T>> of MyTypeTrait<T> {
    fn get_values<TS, T, +ToSpanTrait<TS, T>, +Drop<TS>>(values: TS) -> MyType<T> {
        MyType { values: values.span() }
    }
}

[orizi]

do you have a specific example you ran into?

I rather not add something to the corelib that should probably be removed later.