// 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

// NOTE: This code is derived from an implementation originally in dotnet/runtime:
// https://github.com/dotnet/runtime/blob/v8.0.3/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/InsertionBehavior.cs
//
// See the commentary in https://github.com/dotnet/roslyn/pull/50156 for notes on incorporating changes made to the
// reference implementation.

using System.Collections.Generic;

namespace Microsoft.CodeAnalysis.Collections.Internal
{
    /// <summary>
    /// Used internally to control behavior of insertion into a <see cref="Dictionary{TKey, TValue}"/> or <see cref="HashSet{T}"/>.
    /// </summary>
    internal enum InsertionBehavior : byte
    {
        /// <summary>
        /// The default insertion behavior.
        /// </summary>
        None = 0,

        /// <summary>
        /// Specifies that an existing entry with the same key should be overwritten if encountered.
        /// </summary>
        OverwriteExisting = 1,

        /// <summary>
        /// Specifies that if an existing entry with the same key is encountered, an exception should be thrown.
        /// </summary>
        ThrowOnExisting = 2
    }
}