// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#nullable enable

using System.Runtime.CompilerServices;

namespace Microsoft.CodeAnalysis.Collections.Internal
{
    internal static unsafe class RoslynUnsafe
    {
        /// <summary>
        /// Returns a by-ref to type <typeparamref name="T"/> that is a null reference.
        /// </summary>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static ref T NullRef<T>()
            => ref Unsafe.AsRef<T>(null);

        /// <summary>
        /// Returns if a given by-ref to type <typeparamref name="T"/> is a null reference.
        /// </summary>
        /// <remarks>
        /// This check is conceptually similar to <c>(void*)(&amp;source) == nullptr</c>.
        /// </remarks>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static bool IsNullRef<T>(ref T source)
            => Unsafe.AsPointer(ref source) == null;
    }
}