Span2D<T>

The Span2D<T> is a type that mirrors the functionality of the Span<T> type, but it supports 2D memory regions. Just like Memory2D<T>, it is extremely flexible and can wrap a number of different objects, as well as native pointers or GC references.

The internal layout is similar to that used by the Memory2D<T> type, including a pitch parameter that is used to enable support for discontiguous memory buffers. You can read more info on this in the Memory2D<T> docs.

Platform APIs: Span2D<T>, Memory2D<T>, ReadOnlySpan2D<T>

Syntax

Here's how you can create a Span2D<T> instance from a 2D array:

int[,] array = { { 1, 2, 3 }, { 4, 5, 6 } }; Span2D<int> span = array; // The memory directly maps the 2*3 array here span[0, 0] = 10; span[1, 1] = 20; // The array is now: // { 10, 2, 3 }, // { 4, 20, 6 } // We can also use indices, on supported runtimes int x = span[0, ^1]; // We can also get references to items, like with arrays ref int reference = ref span[1, 1]; Span2D<int> slice = span.Slice(0, 1, 2, 2); // Or alternatively, on supported runtimes slice = span[.., 1..]; int[,] copy = slice.ToArray(); // The resulting array is: // { 2, 3 }, // { 20, 6 } 

We can also directly create a 2D view over native memory:

int* p = stackalloc int[9]; Span2D<int> span = new Span2D<int>(p, 3, 3); 

The Span2D<T> type also includes custom enumerator types to easily traverse a given row, column or the entire memory area using the standard foreach syntax in C#, as well as performing bulk operations in a single call:

int[,] array = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }; Span2D<int> span = array; foreach (int i in span.GetColumn(1)) { // 2, 5, 8 } // We can also iterate by reference foreach (ref int i in span.GetRow(2)) { // 7, 8, 9 } foreach (int i in span) { // 1, 2, 3, 4, 5... } // Set all items in a column to 0 span.GetColumn(0).Clear(); // Set the value of all items in a row span.GetRow(1).Fill(42); Span<int> copy = stackalloc int[3]; // Copy all items from a column span.GetColumn(2).CopyTo(copy); // Get a copy of a row as an array int[] array = span.GetRow(1).ToArray(); 

ReadOnlySpan2D<T>

The ReadOnlySpan2D<T> is to the Span2D<T> type what ReadOnlySpan<T> is to Span<T>. It exposes a similar set of APIs but provides no way to directly modify the contents of the underlying memory area.

Sample Code

You can find more examples in the unit tests.