Drop managed reference linear algebra provider

src/Benchmark/LinearAlgebra/DenseVector.cs

@@ -27,14 +27,13 @@ namespace Benchmark.LinearAlgebra
         public enum ProviderId
         {
             Managed,
-            ManagedReference,
             NativeMKL,
         }
 
         [Params(4, 32, 128, 4096, 16384, 524288)]
         public int N { get; set; }
 
-        [Params(ProviderId.Managed, ProviderId.ManagedReference)] //, ProviderId.NativeMKL)]
+        [Params(ProviderId.Managed)] //, ProviderId.NativeMKL)]
         public ProviderId Provider { get; set; }
 
         double[] _a;
@@ -52,9 +51,6 @@ namespace Benchmark.LinearAlgebra
                 case ProviderId.Managed:
                     Control.UseManaged();
                     break;
-                case ProviderId.ManagedReference:
-                    Control.UseManagedReference();
-                    break;
                 case ProviderId.NativeMKL:
                     MklControl.UseNativeMKL(MklConsistency.Auto, MklPrecision.Double, MklAccuracy.High);
                     break;

src/Numerics/Control.cs

@@ -74,13 +74,6 @@ namespace MathNet.Numerics
             SparseSolverControl.UseManaged();
         }
 
-        public static void UseManagedReference()
-        {
-            LinearAlgebraControl.UseManagedReference();
-            FourierTransformControl.UseManaged();
-            SparseSolverControl.UseManaged();
-        }
-
         /// <summary>
         /// Use a specific provider if configured, e.g. using
         /// environment variables, or fall back to the best providers.

src/Numerics/Providers/LinearAlgebra/LinearAlgebraControl.cs

@@ -88,9 +88,6 @@ namespace MathNet.Numerics.Providers.LinearAlgebra
         public static ILinearAlgebraProvider CreateManaged() => new Managed.ManagedLinearAlgebraProvider();
         public static void UseManaged() => Provider = CreateManaged();
 
-        internal static ILinearAlgebraProvider CreateManagedReference() => new ManagedReference.ManagedReferenceLinearAlgebraProvider();
-        internal static void UseManagedReference() => Provider = CreateManagedReference();
-
         public static void UseNativeMKL() => Provider = MklProbe.Create();
         public static bool TryUseNativeMKL() => TryUse(MklProbe.TryCreate());
 

src/Numerics/Providers/LinearAlgebra/ManagedReference/ManagedReferenceLinearAlgebraProvider.cs

@@ -1,66 +0,0 @@
-// <copyright file="ManagedReferenceLinearAlgebraProvider.cs" company="Math.NET">
-// Math.NET Numerics, part of the Math.NET Project
-// http://numerics.mathdotnet.com
-// http://github.com/mathnet/mathnet-numerics
-//
-// Copyright (c) 2009-2020 Math.NET
-//
-// 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.
-// </copyright>
-
-namespace MathNet.Numerics.Providers.LinearAlgebra.ManagedReference
-{
-    /// <summary>
-    /// The managed linear algebra provider.
-    /// </summary>
-    internal partial class ManagedReferenceLinearAlgebraProvider : ILinearAlgebraProvider
-    {
-        /// <summary>
-        /// Try to find out whether the provider is available, at least in principle.
-        /// Verification may still fail if available, but it will certainly fail if unavailable.
-        /// </summary>
-        public virtual bool IsAvailable()
-        {
-            return true;
-        }
-
-        /// <summary>
-        /// Initialize and verify that the provided is indeed available. If not, fall back to alternatives like the managed provider
-        /// </summary>
-        public virtual void InitializeVerify()
-        {
-        }
-
-        /// <summary>
-        /// Frees memory buffers, caches and handles allocated in or to the provider.
-        /// Does not unload the provider itself, it is still usable afterwards.
-        /// </summary>
-        public virtual void FreeResources()
-        {
-        }
-
-        public override string ToString()
-        {
-            return "Managed";
-        }
-    }
-}