ReadOnlySpan<T> F# snippets (#7823)

Author: albert-du

snippets/fsharp/System/ReadOnlySpanT/GetPinnableReference/fs.fsproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="getpinnablereference1.fs" />
+  </ItemGroup>
+</Project>

snippets/fsharp/System/ReadOnlySpanT/GetPinnableReference/getpinnablereference1.fs

@@ -0,0 +1,44 @@
+#nowarn "9"
+#nowarn "51"
+open System
+open FSharp.NativeInterop
+
+let createInt32Array () =
+    [| 100; 200; 300; 400; 500 |]
+
+[<EntryPoint>]
+let main _ =
+    let array = createInt32Array()
+
+    // Create a span, pin it, and print its elements.
+    let span = array.AsSpan()
+    let spanPtr = &&span.GetPinnableReference()
+    printfn $"Span contains {span.Length} elements:"
+    for i = 0 to span.Length - 1 do
+        printfn $"{NativePtr.get spanPtr i}"
+    printfn ""
+
+    // Create a read-only span, pin it, and print its elements.
+    let readonlyspan: ReadOnlySpan<int> = array.AsSpan()
+    let readonlyspanPtr = &&readonlyspan.GetPinnableReference()
+    
+    printfn $"ReadOnlySpan contains {readonlyspan.Length} elements:"
+    for i = 0 to readonlyspan.Length - 1 do
+        printfn $"{NativePtr.get readonlyspanPtr i}"
+    printfn ""
+    0
+
+// The example displays the following output:
+//       Span contains 5 elements:
+//       100
+//       200
+//       300
+//       400
+//       500
+//
+//       ReadOnlySpan contains 5 elements:
+//       100
+//       200
+//       300
+//       400
+//       500

xml/System/ReadOnlySpan`1.xml

@@ -458,6 +458,7 @@ If pinning a `ReadOnlySpan<char>`, the resulting `char*` __is not__ assumed to b
 The following example demonstrates creating an integer array, pinning it, and writing each element to the console.
 
 :::code language="csharp" source="~/snippets/csharp/System/ReadOnlySpanT/GetPinnableReference/getpinnablereference1.cs":::
+:::code language="fsharp" source="~/snippets/fsharp/System/ReadOnlySpanT/GetPinnableReference/getpinnablereference1.fs":::
 
  ]]></format>
         </remarks>