Consider adding a foreach-like iterator adapter

[steveklabnik]

Proposed in #582 and #1064, the Iterator trait could have a .foreach method which drains the iterator immediately and runs a closure on each element to concisely do so without a for loop.

[gkoz]

Alternatively, there could just be a method to drain the iterator so you wouldn't have to use count or all for that.

[untitaker]

Are there any situations where you wouldn't want to use a for-loop?

[steveklabnik]

It looks much worse when you're working with a chain of iterators.

[ranma42]

I can think of two use cases where it might be convenient more convenient than a for:

• if you just want to run a function you already have:

    for x in values {
        my_log(x)
    }
    values.foreach(my_log)

• if you are doing a pipeline of iterators (it is very common in functional languages, AFAICT not so common in Rust).

[iliekturtles]

See here for reasoning (which I agree with) why the equivalent method wasn't included in .NET's LINQ.

[cuviper]

Iterator::for_each() was merged in rust-lang/rust#42782, tracked in rust-lang/rust#42986.