1 // SPDX-License-Identifier: GPL-2.0
16 /// - `len * size_of::<T>() <= isize::MAX`.
18     len: usize,  field
19     _phantom: PhantomData<fn() -> T>,
23     fn clone(&self) -> Self {  in clone()
29 const ISIZE_MAX: usize = isize::MAX as usize;
33     pub const fn empty() -> Self {  in empty()
34         // INVARIANT: `0 * size_of::<T>() <= isize::MAX`.  in empty()
36             len: 0,  in empty()
41     /// Creates a new layout for `[T; len]`.
45     /// When `len * size_of::<T>()` overflows or when `len * size_of::<T>() > isize::MAX`.
52     /// assert_eq!(layout.len(), 15);
54     /// // Errors because `len * size_of::<T>()` overflows.
55     /// let layout = ArrayLayout::<i32>::new(isize::MAX as usize);
58     /// // Errors because `len * size_of::<i32>() > isize::MAX`,
59     /// // even though `len < isize::MAX`.
60     /// let layout = ArrayLayout::<i32>::new(isize::MAX as usize / 2);
65     pub const fn new(len: usize) -> Result<Self, LayoutError> {  in new()
66         match len.checked_mul(core::mem::size_of::<T>()) {  in new()
68                 // INVARIANT: We checked above that `len * size_of::<T>() <= isize::MAX`.  in new()
70                     len,  in new()
78     /// Creates a new layout for `[T; len]`.
82     /// `len` must be a value, for which `len * size_of::<T>() <= isize::MAX` is true.
83     pub unsafe fn new_unchecked(len: usize) -> Self {  in new_unchecked()
85         // `len * size_of::<T>() <= isize::MAX`.  in new_unchecked()
87             len,  in new_unchecked()
93     pub const fn len(&self) -> usize {  in len()  method
94         self.len  in len()
98     pub const fn is_empty(&self) -> bool {  in is_empty()
99         self.len == 0  in is_empty()
104     fn from(value: ArrayLayout<T>) -> Self {  in from()
105         let res = Layout::array::<T>(value.len);  in from()
107         // `len * size_of::<T>() <= isize::MAX` and thus the result must be `Ok`.  in from()