Collect method implementation for Result type

help
1

While looking at the last example in the documentation for the collect method (at Iterator in std::iter - Rust), I started searching for the implementation of the collect method that makes the collect return the first (and only the first) Err object from a list of Err object (As described at result.rs - source - see definition for FromIterator method).

Could someone point me where in source is such behavior defined ?

2

The impl is here, and the function it calls is found here.

The ResultShunt type it uses is defined right above the process_results function.

3

Ah I misread. The collect function is defined on Iterator and just calls the FromIterator impl directly:

fn collect<B: FromIterator<Self::Item>>(self) -> B
where
    Self: Sized,
{
    FromIterator::from_iter(self)
}

github

4

Thanks @alice. Seems like process_results has the code that has the logic to select the error if it has an error anywhere in the given iterator (using ResultShunt).

Although I am still learning the language (about half way in the Rust book) I would revisit it once I have covered more ground and this would make much more sense to me. Thanks.

5

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