Function to build a fixed sized array from slice [duplicate]

Answer 1

AsMut (or BorrowMut) works:

use std::convert::AsMut;

fn make_array<A, T>(slice: &[T]) -> A
    where A: Sized + Default + AsMut<[T]>,
          T: Copy
{
    let mut a = Default::default();
    // the type cannot be inferred!
    // a.as_mut().copy_from_slice(slice);
    <A as AsMut<[T]>>::as_mut(&mut a).copy_from_slice(slice);
    a
}