slice_trait/
into_boxed_slice.rs

1use crate::AsSlice;
2
3use alloc::{boxed::Box, vec::Vec, alloc::Global};
4
5/// A trait for obtaining a boxed slice `[Self::Elem]`
6pub const trait IntoBoxedSlice: ~const AsSlice + Sized
7{
8    /// Yields boxed slice from generic
9    fn into_boxed_slice(self) -> Box<[Self::Elem]>;
10}
11
12impl<T, const N: usize> IntoBoxedSlice for [T; N]
13{
14    fn into_boxed_slice(self) -> Box<[Self::Elem]>
15    {
16        let mut boxed = Box::new_in(self, Global);
17        let ptr = boxed.as_mut_ptr();
18        core::mem::forget(boxed);
19        unsafe {
20            Box::from_raw_in(core::ptr::from_raw_parts_mut(ptr, N), Global)
21        }
22    }
23}
24
25impl<T> const IntoBoxedSlice for Box<[T]>
26{
27    fn into_boxed_slice(self) -> Box<[Self::Elem]>
28    {
29        self
30    }
31}
32
33impl<T> /*const*/ IntoBoxedSlice for Vec<T>
34{
35    fn into_boxed_slice(mut self) -> Box<[Self::Elem]>
36    {
37        self.shrink_to_fit();
38
39        let (ptr, len, cap, alloc) = self.into_raw_parts_with_alloc();
40        assert_eq!(len, cap, "Memory leak detected");
41
42        unsafe {
43            Box::from_raw_in(core::ptr::from_raw_parts_mut(ptr, len), alloc)
44        }
45    }
46}
slice_trait/into_boxed_slice.rs

slice_trait/
into_boxed_slice.rs
