Cached.cs

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System.Collections.ObjectModel;
using System.Runtime.CompilerServices;

namespace DocumentFormat.OpenXml.Framework
{
    internal static class Cached
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static T[] Array<T>() => System.Array.Empty<T>();

        public static ReadOnlyCollection<T> ReadOnlyCollection<T>() => ReadOnlyCollectionCache<T>.Value;

        private static class ReadOnlyCollectionCache<T>
        {
            internal static readonly ReadOnlyCollection<T> Value = new ReadOnlyCollection<T>(Array<T>());
        }
    }
}