Function inplace_it::inplace_or_alloc_from_iter

pub fn inplace_or_alloc_from_iter<Iter, R, Consumer>(
    iter: Iter, 
    consumer: Consumer
) -> R where
    Iter: Iterator,
    Consumer: FnOnce(&mut [Iter::Item]) -> R, 

inplace_or_alloc_from_iter is helper function used to easy trying to place data from Iterator.

It tries to get upper bound of size_hint of iterator and forward it to inplace_or_alloc_array function. It there is not upper bound hint from iterator, then it just collect your data into Vec.

If iterator contains more data that size_hint said (and more than try_inplace_array function placed on stack), then items will be moved and collected (by iterating) into Vec also.

Examples

// Some random number to demonstrate
let count = 42;
let iterator = 0..count;

let result = ::inplace_it::inplace_or_alloc_from_iter(iterator.clone(), |mem| {
     assert_eq!(mem.len(), count);
     assert!(mem.iter().cloned().eq(iterator));

     // Some result
     format!("{}", mem.len())
 });
 assert_eq!(result, format!("{}", count));