use inplace_it::{inplace_or_alloc_array, UninitializedSliceMemoryGuard};

inplace_or_alloc_array(
    150, // size of needed array to allocate
    |mut uninit_guard: UninitializedSliceMemoryGuard<u16>| { // and this is consumer of uninitialized memory

        // Size of stack-allocated memory can be more or equal to requested, but never less.
        assert_eq!(160, uninit_guard.len());
        
        {
         // You can borrow guard to reuse memory
         let borrowed_uninit_guard = uninit_guard.borrow();
         // Let's initialize memory
         // Note that borrowed_uninit_guard will be consumed (destroyed to produce initialized memory guard)
         let init_guard = borrowed_uninit_guard.init(|index| index as u16 + 1);
         // Memory now contains elements [1, 2, ..., 160]
         // Lets check it. Sum of [1, 2, ..., 160] = 12880
         let sum: u16 = init_guard.iter().sum();
         assert_eq!(sum, 12880);
        }
        
        {
         // If you don't want to reuse memory, you can init new guard directly
         let init_guard = uninit_guard.init(|index| index as u16 * 2);
         // Memory now contains elements [0, 2, 4, ..., 318]
         // Lets check it. Sum of [0, 2, 4, ..., 318] = 25440
         let sum: u16 = init_guard.iter().sum();
         assert_eq!(sum, 25440);
        }
    }
)