Function inplace_it::inplace_copy_of

pub fn inplace_copy_of<T: Clone, R, Consumer: FnOnce(&mut [T]) -> R>(
    source: &[T], 
    limit: usize, 
    consumer: Consumer
) -> R

inplace_copy_of trying to place an array of T on the stack, then initialize it by copying from the source slice and finally pass the reference to it into the consumer closure. Length of source argument sets the requested size of an array. consumer's result will be returned.

If the result of array of T is more than limit (or it's size is more than 4096) then the vector will be allocated in the heap and will be initialized and passed as a reference instead of stack-based fixed-size array.

It's shrink placed/allocated memory by inplace_array_uninitialized to requested size so you don't need to worry about extra memory, just use it.

Examples

use inplace_it::{ inplace_array, inplace_copy_of };

for i in (0..500).step_by(25) {
    // we use `inplace_array` for generating inputs
    inplace_array(i, 1024, |index| index, |memory: &mut [usize]| {
        assert_eq!(memory.len(), i);
        inplace_copy_of(
            memory, // source which will be used for setting size and initializing an array
            1024, // limit of allowed stack allocation in bytes,
            |memory_copy: &mut [usize]| {
                assert_eq!(memory, memory_copy);
            },
        );
    });
}