// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT license.

using System;

using System.Collections.Generic;

using System.Runtime.InteropServices;

namespace Microsoft.ClearScript.Util.COM

{

internal static class StructHelpers

{

public delegate void GetStruct(out IntPtr pStruct);

public delegate void ReleaseStruct(IntPtr pStruct);

public static IScope<T> CreateScope<T>(GetStruct get, ReleaseStruct release)

{

get(out var pStruct);

return Scope.Create(() => (T)Marshal.PtrToStructure(pStruct, typeof(T)), _ => release(pStruct));

}

public static IEnumerable<T> GetStructsFromArray<T>(IntPtr pStructs, int count)

{

var size = Marshal.SizeOf(typeof(T));

for (var pStruct = pStructs; count > 0; count--)

{

yield return (T)Marshal.PtrToStructure(pStruct, typeof(T));

pStruct += size;

}

}

}

}