simplify Iterators definition

[gwbres]

Simplify returned type, when we return an Iterator : it never requires it to be Box'ed

• Answers RINEX: simplify Iterators definition to return "impl Iterator"  #142

[gwbres]

@lnicola,

there are a few spots where I can't see to remove the Box, why is that ?

For example, this does not compile

Hum.. this raises severe problems

[lnicola]

Yeah, that won't work. The reason is that impl Iterator is always a single type, but the code in the screenshot would return 5 different types. TBH, maybe Box<dyn Iterator> is not a a terrible choice, as some people don't really like impl Trait return types anyway. I was just pointing out it's an option there.

[gwbres]

The reason is that impl Iterator is always a single type, but the code in the screenshot would return 5 different types

the returned type is the same, in the sense they're all Iterators over an Epoch, but the iterator source is different that is true

[lnicola]

The closures are also different types, even if they have the same arguments and return value (and I'm not sure these ones do).