mono/netcore/System.Private.CoreLib/shared/System/ObsoleteAttribute.cs

// 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.

/*============================================================
**
**
**
** Purpose: Attribute for functions, etc that will be removed.
**
**
===========================================================*/

namespace System
{
    // This attribute is attached to members that are not to be used any longer.
    // Message is some human readable explanation of what to use
    // Error indicates if the compiler should treat usage of such a method as an
    //   error. (this would be used if the actual implementation of the obsolete
    //   method's implementation had changed).
    //
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum |
        AttributeTargets.Interface | AttributeTargets.Constructor | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Delegate,
        Inherited = false)]
    public sealed class ObsoleteAttribute : Attribute
    {
        private readonly string? _message;
        private readonly bool _error;

        public ObsoleteAttribute()
        {
            _message = null;
            _error = false;
        }

        public ObsoleteAttribute(string? message)
        {
            _message = message;
            _error = false;
        }

        public ObsoleteAttribute(string? message, bool error)
        {
            _message = message;
            _error = error;
        }

        public string? Message => _message;

        public bool IsError => _error;
    }
}