//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="ValueBox.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. All rights reserved.
//     
//     Permission is hereby granted, free of charge, to any person 
//     obtaining a copy of this software and associated documentation 
//     files (the “Software”), to deal in the Software without restriction, 
//     including without limitation the rights to use, copy, modify, merge,
//     publish, distribute, sublicense, and/or sell copies of the Software, 
//     and to permit persons to whom the Software is furnished to do so, 
//     subject to the following conditions:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//     ARISING FROM, OUT OF OR IN CONNECTION WITH 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Data
{
    public interface IValueBox
    {

        ref object ValueReference
        {
            get;
        }

        static virtual IValueBox<T> AsGeneric<T>( IValueBox box )
            where T: struct
        {
            if( box is not IValueBox<T> genericBox ) {
                return null;
            }
            return genericBox;
        }

        static virtual bool IsGeneric<T>( IValueBox box ) where T: struct
        {
            return box is IValueBox<T>;
        }

    }

    public interface IValueBox<T> where T: struct
    {

        T Value
        {
            get;
            set;
        }

    }

    /// <summary>
    /// A class attempt to reduce cost of boxing, though still a bit slower than direct access to
    /// _origin value type instance.
    /// </summary>
    /// <typeparam name="T"> Type of instance to be boxed. </typeparam>
    public class ValueBox<T> : IValueBox, IValueBox<T> where T: struct
    {

        private T _value;

        public ValueBox( T value )
        {
            _value = value;
        }

        public ref object ValueReference => ref Unsafe.As<T, object>(
            ref _value );

        public T Value
        {
            get => _value;
            set => _value = value;
        }

    }
}