diff --git a/netstandard/src/ApiCompatBaseline.net461.txt b/netstandard/src/ApiCompatBaseline.net461.txt
index e09c2ca8b..ba4fbd892 100644
--- a/netstandard/src/ApiCompatBaseline.net461.txt
+++ b/netstandard/src/ApiCompatBaseline.net461.txt
@@ -2,16 +2,6 @@ Compat issues with assembly netstandard:
 MembersMustExist : Member 'System.AppContext.GetData(System.String)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.AppContext.TargetFrameworkName.get()' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.StringNormalizationExtensions' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.TupleExtensions' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3, T4>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3, T4, T5>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3, T4, T5, T6>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Data.Common.DbColumn' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Data.Common.DbDataReaderExtensions' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Data.Common.IDbColumnSchemaGenerator' does not exist in the implementation but it does exist in the contract.
@@ -41,10 +31,6 @@ MembersMustExist : Member 'System.Net.Http.HttpClientHandler.SslProtocols.set(Sy
 TypesMustExist : Type 'System.Net.Sockets.SocketReceiveFromResult' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Net.Sockets.SocketReceiveMessageFromResult' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Net.Sockets.SocketTaskExtensions' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.Runtime.CompilerServices.TupleElementNamesAttribute' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.Runtime.InteropServices.Architecture' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.Runtime.InteropServices.OSPlatform' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'System.Runtime.InteropServices.RuntimeInformation' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Runtime.Serialization.DataContractSerializerExtensions' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Runtime.Serialization.ISerializationSurrogateProvider' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Security.SecureStringMarshal' does not exist in the implementation but it does exist in the contract.
@@ -65,4 +51,4 @@ MembersMustExist : Member 'System.Text.RegularExpressions.Regex.Caps.set(System.
 TypesMustExist : Type 'System.Threading.PreAllocatedOverlapped' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Threading.ThreadPoolBoundHandle' does not exist in the implementation but it does exist in the contract.
 TypesMustExist : Type 'System.Xml.XPath.XDocumentExtensions' does not exist in the implementation but it does exist in the contract.
-Total Issues: 66
+Total Issues: 52
diff --git a/netstandard/src/GenApi.exclude.net461.txt b/netstandard/src/GenApi.exclude.net461.txt
index bb7f3cf00..548768637 100644
--- a/netstandard/src/GenApi.exclude.net461.txt
+++ b/netstandard/src/GenApi.exclude.net461.txt
@@ -21,19 +21,4 @@ T:System.Security.Cryptography.IncrementalHash
 T:System.Security.Cryptography.TripleDESCng
 T:System.Threading.PreAllocatedOverlapped
 T:System.Threading.ThreadPoolBoundHandle
-T:System.Xml.XPath.XDocumentExtensions
-T:System.Runtime.InteropServices.Architecture
-T:System.Runtime.InteropServices.OSPlatform
-T:System.Runtime.InteropServices.RuntimeInformation
-T:System.TupleExtensions
-T:System.ValueTuple
-T:System.ValueTuple`1
-T:System.ValueTuple`1
-T:System.ValueTuple`2
-T:System.ValueTuple`3
-T:System.ValueTuple`4
-T:System.ValueTuple`5
-T:System.ValueTuple`6
-T:System.ValueTuple`7
-T:System.ValueTuple`8
-T:System.Runtime.CompilerServices.TupleElementNamesAttribute
\ No newline at end of file
+T:System.Xml.XPath.XDocumentExtensions
\ No newline at end of file
diff --git a/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.cs b/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.cs
new file mode 100644
index 000000000..75bee41b9
--- /dev/null
+++ b/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.cs
@@ -0,0 +1,36 @@
+// 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.
+
+namespace System.Runtime.InteropServices
+{
+    public enum Architecture
+    {
+        Arm = 2,
+        Arm64 = 3,
+        X64 = 1,
+        X86 = 0,
+    }
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct OSPlatform : System.IEquatable<System.Runtime.InteropServices.OSPlatform>
+    {
+        public static System.Runtime.InteropServices.OSPlatform Linux { get { throw null; } }
+        public static System.Runtime.InteropServices.OSPlatform OSX { get { throw null; } }
+        public static System.Runtime.InteropServices.OSPlatform Windows { get { throw null; } }
+        public static System.Runtime.InteropServices.OSPlatform Create(string osPlatform) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.Runtime.InteropServices.OSPlatform other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        public static bool operator ==(System.Runtime.InteropServices.OSPlatform left, System.Runtime.InteropServices.OSPlatform right) { throw null; }
+        public static bool operator !=(System.Runtime.InteropServices.OSPlatform left, System.Runtime.InteropServices.OSPlatform right) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public static partial class RuntimeInformation
+    {
+        public static string FrameworkDescription { get { throw null; } }
+        public static System.Runtime.InteropServices.Architecture OSArchitecture { get { throw null; } }
+        public static string OSDescription { get { throw null; } }
+        public static System.Runtime.InteropServices.Architecture ProcessArchitecture { get { throw null; } }
+        public static bool IsOSPlatform(System.Runtime.InteropServices.OSPlatform osPlatform) { throw null; }
+    }
+}
diff --git a/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.csproj b/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.csproj
new file mode 100644
index 000000000..c8786aa87
--- /dev/null
+++ b/platforms/net461/System.Runtime.InteropServices.RuntimeInformation.csproj
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <OutputType>Library</OutputType>
+    <!-- disable obsolete warnings/errors -->
+    <NoWarn>$(NoWarn);0618;0619;0809</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="mscorlib.csproj" />
+    <Compile Include="System.Runtime.InteropServices.RuntimeInformation.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
\ No newline at end of file
diff --git a/platforms/net461/System.ValueTuple.cs b/platforms/net461/System.ValueTuple.cs
new file mode 100644
index 000000000..364f8f454
--- /dev/null
+++ b/platforms/net461/System.ValueTuple.cs
@@ -0,0 +1,267 @@
+// 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.
+
+namespace System
+{
+    public static partial class TupleExtensions
+    {
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1>(this System.Tuple<T1> value, out T1 item1) { item1 = default(T1); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16, out T17 item17) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); item17 = default(T17); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16, out T17 item17, out T18 item18) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); item17 = default(T17); item18 = default(T18); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16, out T17 item17, out T18 item18, out T19 item19) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); item17 = default(T17); item18 = default(T18); item19 = default(T19); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2>(this System.Tuple<T1, T2> value, out T1 item1, out T2 item2) { item1 = default(T1); item2 = default(T2); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16, out T17 item17, out T18 item18, out T19 item19, out T20 item20) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); item17 = default(T17); item18 = default(T18); item19 = default(T19); item20 = default(T20); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, T21>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20, T21>>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9, out T10 item10, out T11 item11, out T12 item12, out T13 item13, out T14 item14, out T15 item15, out T16 item16, out T17 item17, out T18 item18, out T19 item19, out T20 item20, out T21 item21) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); item10 = default(T10); item11 = default(T11); item12 = default(T12); item13 = default(T13); item14 = default(T14); item15 = default(T15); item16 = default(T16); item17 = default(T17); item18 = default(T18); item19 = default(T19); item20 = default(T20); item21 = default(T21); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3>(this System.Tuple<T1, T2, T3> value, out T1 item1, out T2 item2, out T3 item3) { item1 = default(T1); item2 = default(T2); item3 = default(T3); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4>(this System.Tuple<T1, T2, T3, T4> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5>(this System.Tuple<T1, T2, T3, T4, T5> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6>(this System.Tuple<T1, T2, T3, T4, T5, T6> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); }
+        [System.ComponentModel.EditorBrowsableAttribute((System.ComponentModel.EditorBrowsableState)(1))]
+        public static void Deconstruct<T1, T2, T3, T4, T5, T6, T7, T8, T9>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9>> value, out T1 item1, out T2 item2, out T3 item3, out T4 item4, out T5 item5, out T6 item6, out T7 item7, out T8 item8, out T9 item9) { item1 = default(T1); item2 = default(T2); item3 = default(T3); item4 = default(T4); item5 = default(T5); item6 = default(T6); item7 = default(T7); item8 = default(T8); item9 = default(T9); }
+        public static System.Tuple<T1> ToTuple<T1>(this System.ValueTuple<T1> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19>>> value) { throw null; }
+        public static System.Tuple<T1, T2> ToTuple<T1, T2>(this System.ValueTuple<T1, T2> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19, T20>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20, T21>>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, T21>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19, T20, T21>>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3> ToTuple<T1, T2, T3>(this System.ValueTuple<T1, T2, T3> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4> ToTuple<T1, T2, T3, T4>(this System.ValueTuple<T1, T2, T3, T4> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5> ToTuple<T1, T2, T3, T4, T5>(this System.ValueTuple<T1, T2, T3, T4, T5> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6> ToTuple<T1, T2, T3, T4, T5, T6>(this System.ValueTuple<T1, T2, T3, T4, T5, T6> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7> ToTuple<T1, T2, T3, T4, T5, T6, T7>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8>> value) { throw null; }
+        public static System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9>> ToTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9>(this System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9>> value) { throw null; }
+        public static System.ValueTuple<T1> ToValueTuple<T1>(this System.Tuple<T1> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2> ToValueTuple<T1, T2>(this System.Tuple<T1, T2> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19, T20>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9, T10, T11, T12, T13, T14, System.ValueTuple<T15, T16, T17, T18, T19, T20, T21>>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, T21>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9, T10, T11, T12, T13, T14, System.Tuple<T15, T16, T17, T18, T19, T20, T21>>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3> ToValueTuple<T1, T2, T3>(this System.Tuple<T1, T2, T3> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4> ToValueTuple<T1, T2, T3, T4>(this System.Tuple<T1, T2, T3, T4> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5> ToValueTuple<T1, T2, T3, T4, T5>(this System.Tuple<T1, T2, T3, T4, T5> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6> ToValueTuple<T1, T2, T3, T4, T5, T6>(this System.Tuple<T1, T2, T3, T4, T5, T6> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7> ToValueTuple<T1, T2, T3, T4, T5, T6, T7>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8>> value) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8, T9>> ToValueTuple<T1, T2, T3, T4, T5, T6, T7, T8, T9>(this System.Tuple<T1, T2, T3, T4, T5, T6, T7, System.Tuple<T8, T9>> value) { throw null; }
+    }
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Size=1)]
+    public partial struct ValueTuple : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple>, System.IEquatable<System.ValueTuple>
+    {
+        public int CompareTo(System.ValueTuple other) { throw null; }
+        public static System.ValueTuple Create() { throw null; }
+        public static System.ValueTuple<T1> Create<T1>(T1 item1) { throw null; }
+        public static System.ValueTuple<T1, T2> Create<T1, T2>(T1 item1, T2 item2) { throw null; }
+        public static System.ValueTuple<T1, T2, T3> Create<T1, T2, T3>(T1 item1, T2 item2, T3 item3) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4> Create<T1, T2, T3, T4>(T1 item1, T2 item2, T3 item3, T4 item4) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5> Create<T1, T2, T3, T4, T5>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6> Create<T1, T2, T3, T4, T5, T6>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7> Create<T1, T2, T3, T4, T5, T6, T7>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7) { throw null; }
+        public static System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, System.ValueTuple<T8>> Create<T1, T2, T3, T4, T5, T6, T7, T8>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7, T8 item8) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct ValueTuple<T1> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1>>, System.IEquatable<System.ValueTuple<T1>>
+    {
+        public T1 Item1;
+        public ValueTuple(T1 item1) { throw null;}
+        public int CompareTo(System.ValueTuple<T1> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2>>, System.IEquatable<System.ValueTuple<T1, T2>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public ValueTuple(T1 item1, T2 item2) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3>>, System.IEquatable<System.ValueTuple<T1, T2, T3>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public ValueTuple(T1 item1, T2 item2, T3 item3) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3, T4> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public T4 Item4;
+        public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3, T4> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3, T4> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3, T4, T5> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4, T5>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4, T5>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public T4 Item4;
+        public T5 Item5;
+        public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3, T4, T5> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3, T4, T5, T6> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4, T5, T6>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4, T5, T6>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public T4 Item4;
+        public T5 Item5;
+        public T6 Item6;
+        public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5, T6> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3, T4, T5, T6> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>>
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public T4 Item4;
+        public T5 Item5;
+        public T6 Item6;
+        public T7 Item7;
+        public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+    public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>> where TRest : struct
+    {
+        public T1 Item1;
+        public T2 Item2;
+        public T3 Item3;
+        public T4 Item4;
+        public T5 Item5;
+        public T6 Item6;
+        public T7 Item7;
+        public TRest Rest;
+        public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7, TRest rest) { throw null;}
+        public int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        int System.Collections.IStructuralComparable.CompareTo(object other, System.Collections.IComparer comparer) { throw null; }
+        bool System.Collections.IStructuralEquatable.Equals(object other, System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        int System.IComparable.CompareTo(object other) { throw null; }
+        public override string ToString() { throw null; }
+    }
+}
+namespace System.Runtime.CompilerServices
+{
+    [System.AttributeUsageAttribute((System.AttributeTargets)(11148))]
+    [System.CLSCompliantAttribute(false)]
+    public sealed partial class TupleElementNamesAttribute : System.Attribute
+    {
+        public TupleElementNamesAttribute(string[] transformNames) { }
+        public System.Collections.Generic.IList<string> TransformNames { get { throw null; } }
+    }
+}
diff --git a/platforms/net461/System.ValueTuple.csproj b/platforms/net461/System.ValueTuple.csproj
new file mode 100644
index 000000000..2324b2194
--- /dev/null
+++ b/platforms/net461/System.ValueTuple.csproj
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <OutputType>Library</OutputType>
+    <!-- disable obsolete warnings/errors -->
+    <NoWarn>$(NoWarn);0618;0619;0809</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="mscorlib.csproj" />
+    <ProjectReference Include="System.csproj" />
+    <Compile Include="System.ValueTuple.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+</Project>
\ No newline at end of file