1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83
/// Array order /// /// Order refers to indexing order, or how a linear sequence is translated /// into a two-dimensional or multi-dimensional array. /// /// - `RowMajor` means that the index along the row is the most rapidly changing /// - `ColumnMajor` means that the index along the column is the most rapidly changing /// /// Given a sequence like: 1, 2, 3, 4, 5, 6 /// /// If it is laid it out in a 2 x 3 matrix using row major ordering, it results in: /// /// ```text /// 1 2 3 /// 4 5 6 /// ``` /// /// If it is laid using column major ordering, it results in: /// /// ```text /// 1 3 5 /// 2 4 6 /// ``` /// /// It can be seen as filling in "rows first" or "columns first". /// /// `Order` can be used both to refer to logical ordering as well as memory ordering or memory /// layout. The orderings have common short names, also seen in other environments, where /// row major is called "C" order (after the C programming language) and column major is called "F" /// or "Fortran" order. #[derive(Copy, Clone, Debug, PartialEq, Eq)] #[non_exhaustive] pub enum Order { /// Row major or "C" order RowMajor, /// Column major or "F" order ColumnMajor, } impl Order { /// "C" is an alias for row major ordering pub const C: Order = Order::RowMajor; /// "F" (for Fortran) is an alias for column major ordering pub const F: Order = Order::ColumnMajor; /// Return true if input is Order::RowMajor, false otherwise #[inline] pub fn is_row_major(self) -> bool { match self { Order::RowMajor => true, Order::ColumnMajor => false, } } /// Return true if input is Order::ColumnMajor, false otherwise #[inline] pub fn is_column_major(self) -> bool { !self.is_row_major() } /// Return Order::RowMajor if the input is true, Order::ColumnMajor otherwise #[inline] pub fn row_major(row_major: bool) -> Order { if row_major { Order::RowMajor } else { Order::ColumnMajor } } /// Return Order::ColumnMajor if the input is true, Order::RowMajor otherwise #[inline] pub fn column_major(column_major: bool) -> Order { Self::row_major(!column_major) } /// Return the transpose: row major becomes column major and vice versa. #[inline] pub fn transpose(self) -> Order { match self { Order::RowMajor => Order::ColumnMajor, Order::ColumnMajor => Order::RowMajor, } } }