std::iter::map rust run parallelly?

Question

I have been searching to find parallelizes map in rust most answer point to rayon crate so I wonder if std::iter::map iterate sequentially by default?

Answer 1

I wonder if std::iter::map iterate sequentially by default?

It does

Rust iterators are lazy, meaning that nothing is computed unless asked explicitly. And they are computed one by one until the iterator is exhausted.

Map , from the documentation:

An iterator that maps the values of iter with f

Is an iterator adaptor, it will apply a transformation function on each item of the iterator one by one (when requested, through the next method).