Create aligned Vec instance

aligned_vec.rs

// Create aligned Vec
fn main() {
    let ivec: Vec<i32> = aligned_vec(2048, 4096, 256);
    assert!(ivec.as_ptr() as u64 % 256 == 0);
}
pub fn aligned_vec<T: Sized>(size: usize, capacity: usize, align: usize) -> Vec<T> {
    unsafe {
        if size == 0 {
            Vec::<T>::new()
        } else {
            let size = size * std::mem::size_of::<T>();
            let capacity = (capacity * std::mem::size_of::<T>()).max(size);

            let layout = std::alloc::Layout::from_size_align_unchecked(size, align);
            let raw_ptr = std::alloc::alloc(layout) as *mut T;
            Vec::from_raw_parts(raw_ptr, size, capacity)
        }
    }
}
//use crate page_size to retrieve system page size