Tuples! (#15075)

Use tuple syntax in the compiler

src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using Microsoft.CodeAnalysis.Collections;
-using Microsoft.CodeAnalysis.CSharp.Symbols;
-using Microsoft.CodeAnalysis.CSharp.Syntax;
-using Microsoft.CodeAnalysis.RuntimeMembers;
-using Roslyn.Utilities;
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.CodeAnalysis.Collections;
+using Microsoft.CodeAnalysis.CSharp.Symbols;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.RuntimeMembers;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {
@@ -755,13 +755,14 @@ private Symbol UnwrapAlias(Symbol symbol, out AliasSymbol alias, DiagnosticBag d
                 if ((object)type != null)
                 {
                     // pass args in a value tuple to avoid allocating a closure
-                    var args = ValueTuple.Create(this, diagnostics, syntax);
+                    var args = (this, diagnostics, syntax);
                     type.VisitType((typePart, argTuple, isNested) =>
                     {
                         argTuple.Item1.ReportDiagnosticsIfObsolete(argTuple.Item2, typePart, argTuple.Item3, hasBaseReceiver: false);
                         return false;
                     }, args);
                 }
+
                 return result;
             }
 
@@ -2098,4 +2099,4 @@ internal static void CheckFeatureAvailability(Location location, MessageID featu
             }
         }
     }
-}
+}
\ No newline at end of file

src/Compilers/CSharp/Portable/CodeGen/Optimizer.cs

@@ -388,7 +388,7 @@ internal enum ExprContext
     internal sealed class StackOptimizerPass1 : BoundTreeRewriter
     {
         private readonly bool _debugFriendly;
-        private readonly ArrayBuilder<ValueTuple<BoundExpression, ExprContext>> _evalStack;
+        private readonly ArrayBuilder<(BoundExpression, ExprContext)> _evalStack;
 
         private int _counter;
         private ExprContext _context;
@@ -535,7 +535,7 @@ protected override BoundExpression VisitExpressionWithoutStackGuard(BoundExpress
         private void PushEvalStack(BoundExpression result, ExprContext context)
         {
             Debug.Assert(result != null || context == ExprContext.None);
-            _evalStack.Add(ValueTuple.Create(result, context));
+            _evalStack.Add((result, context));
         }
 
         private int StackDepth()

src/Compilers/CSharp/Portable/Compilation/CSharpCompilation.cs

@@ -849,13 +849,8 @@ public override ImmutableArray<MetadataReference> DirectiveReferences
             }
         }
 
-        internal override IDictionary<ValueTuple<string, string>, MetadataReference> ReferenceDirectiveMap
-        {
-            get
-            {
-                return GetBoundReferenceManager().ReferenceDirectiveMap;
-            }
-        }
+        internal override IDictionary<(string path, string content), MetadataReference> ReferenceDirectiveMap
+            => GetBoundReferenceManager().ReferenceDirectiveMap;
 
         // for testing purposes
         internal IEnumerable<string> ExternAliases
@@ -916,7 +911,7 @@ internal override IEnumerable<ReferenceDirective> ReferenceDirectives
         public MetadataReference GetDirectiveReference(ReferenceDirectiveTriviaSyntax directive)
         {
             MetadataReference reference;
-            return ReferenceDirectiveMap.TryGetValue(ValueTuple.Create(directive.SyntaxTree.FilePath, directive.File.ValueText), out reference) ? reference : null;
+            return ReferenceDirectiveMap.TryGetValue((directive.SyntaxTree.FilePath, directive.File.ValueText), out reference) ? reference : null;
         }
 
         /// <summary>

src/Compilers/CSharp/Portable/Emitter/Model/PEModuleBuilder.cs

@@ -555,7 +555,7 @@ private void ReportExportedTypeNameCollisions(ImmutableArray<Cci.ExportedType> e
             if (wellKnownAttributeData?.ForwardedTypes?.Count > 0)
             {
                 // (type, index of the parent exported type in builder, or -1 if the type is a top-level type)
-                var stack = ArrayBuilder<ValueTuple<NamedTypeSymbol, int>>.GetInstance();
+                var stack = ArrayBuilder<(NamedTypeSymbol type, int parentIndex)>.GetInstance();
 
                 foreach (NamedTypeSymbol forwardedType in wellKnownAttributeData.ForwardedTypes)
                 {
@@ -569,13 +569,11 @@ private void ReportExportedTypeNameCollisions(ImmutableArray<Cci.ExportedType> e
                     // Return all nested types.
                     // Note the order: depth first, children in reverse order (to match dev10, not a requirement).
                     Debug.Assert(stack.Count == 0);
-                    stack.Push(ValueTuple.Create(originalDefinition, -1));
+                    stack.Push((originalDefinition, -1));
 
                     while (stack.Count > 0)
                     {
-                        var entry = stack.Pop();
-                        NamedTypeSymbol type = entry.Item1;
-                        int parentIndex = entry.Item2;
+                        var (type, parentIndex) = stack.Pop();
 
                         // In general, we don't want private types to appear in the ExportedTypes table.
                         // BREAK: dev11 emits these types.  The problem was discovered in dev10, but failed
@@ -595,7 +593,7 @@ private void ReportExportedTypeNameCollisions(ImmutableArray<Cci.ExportedType> e
                         ImmutableArray<NamedTypeSymbol> nested = type.GetTypeMembers(); // Ordered.
                         for (int i = nested.Length - 1; i >= 0; i--)
                         {
-                            stack.Push(ValueTuple.Create(nested[i], index));
+                            stack.Push((nested[i], index));
                         }
                     }
                 }

src/Compilers/CSharp/Portable/Symbols/ReferenceManager.cs

@@ -345,7 +345,7 @@ private bool CreateAndSetSourceAssemblyFullBind(CSharpCompilation compilation)
 
                 try
                 {
-                    IDictionary<ValueTuple<string, string>, MetadataReference> boundReferenceDirectiveMap;
+                    IDictionary<(string, string), MetadataReference> boundReferenceDirectiveMap;
                     ImmutableArray<MetadataReference> boundReferenceDirectives;
                     ImmutableArray<AssemblyData> referencedAssemblies;
                     ImmutableArray<PEModule> modules; // To make sure the modules are not collected ahead of time.

src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol.cs

@@ -1047,7 +1047,7 @@ public override ImmutableArray<NamedTypeSymbol> GetTypeMembers(string name, int
         private Dictionary<string, ImmutableArray<NamedTypeSymbol>> MakeTypeMembers(DiagnosticBag diagnostics)
         {
             var symbols = ArrayBuilder<NamedTypeSymbol>.GetInstance();
-            var conflictDict = new Dictionary<ValueTuple<string, int>, SourceNamedTypeSymbol>();
+            var conflictDict = new Dictionary<(string, int), SourceNamedTypeSymbol>();
             try
             {
                 foreach (var childDeclaration in declaration.Children)
@@ -1055,7 +1055,7 @@ public override ImmutableArray<NamedTypeSymbol> GetTypeMembers(string name, int
                     var t = new SourceNamedTypeSymbol(this, childDeclaration, diagnostics);
                     this.CheckMemberNameDistinctFromType(t, diagnostics);
 
-                    var key = new ValueTuple<string, int>(t.Name, t.Arity);
+                    var key = (t.Name, t.Arity);
                     SourceNamedTypeSymbol other;
                     if (conflictDict.TryGetValue(key, out other))
                     {

src/Compilers/Core/Portable/CodeAnalysis.csproj

@@ -418,9 +418,6 @@
     <Compile Include="InternalUtilities\ThreadSafeFlagOperations.cs" />
     <Compile Include="InternalUtilities\ThreeState.cs" />
     <Compile Include="InternalUtilities\UICultureUtilities.cs" />
-    <Compile Include="InternalUtilities\ValueTuple.cs" />
-    <Compile Include="InternalUtilities\ValueTuple`2.cs" />
-    <Compile Include="InternalUtilities\ValueTuple`3.cs" />
     <Compile Include="InternalUtilities\WeakList.cs" />
     <Compile Include="InternalUtilities\WeakReferenceExtensions.cs" />
     <Compile Include="InternalUtilities\XmlUtilities.cs" />

src/Compilers/Core/Portable/CodeGen/ArrayMembers.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using Roslyn.Utilities;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
@@ -93,15 +94,15 @@ public ArrayMethod GetArrayAddress(Cci.IArrayTypeReference arrayType)
         /// <summary>
         /// Maps {array type, method kind} tuples to implementing pseudo-methods.
         /// </summary>
-        private readonly ConcurrentDictionary<ValueTuple<byte, Cci.IArrayTypeReference>, ArrayMethod> _dict =
-            new ConcurrentDictionary<ValueTuple<byte, Cci.IArrayTypeReference>, ArrayMethod>();
+        private readonly ConcurrentDictionary<(byte methodKind, Cci.IArrayTypeReference arrayType), ArrayMethod> _dict =
+            new ConcurrentDictionary<(byte, Cci.IArrayTypeReference), ArrayMethod>();
 
         /// <summary>
         /// lazily fetches or creates a new array method.
         /// </summary>
         private ArrayMethod GetArrayMethod(Cci.IArrayTypeReference arrayType, ArrayMethodKind id)
         {
-            var key = ValueTuple.Create((byte)id, arrayType);
+            var key = ((byte)id, arrayType);
             ArrayMethod result;
 
             var dict = _dict;

src/Compilers/Core/Portable/Compilation/Compilation.cs

@@ -501,7 +501,7 @@ internal CommonReferenceManager GetBoundReferenceManager()
         /// <summary>
         /// Maps values of #r references to resolved metadata references.
         /// </summary>
-        internal abstract IDictionary<ValueTuple<string, string>, MetadataReference> ReferenceDirectiveMap { get; }
+        internal abstract IDictionary<(string path, string content), MetadataReference> ReferenceDirectiveMap { get; }
 
         /// <summary>
         /// All metadata references -- references passed to the compilation

src/Compilers/Core/Portable/Emit/DebugDocumentsBuilder.cs

@@ -17,7 +17,7 @@ internal sealed class DebugDocumentsBuilder
         // NOTE: We are not considering how filesystem or debuggers do the comparisons, but how native implementations did.
         // Deviating from that may result in unexpected warnings or different behavior (possibly without warnings).
         private readonly ConcurrentDictionary<string, Cci.DebugSourceDocument> _debugDocuments;
-        private readonly ConcurrentCache<ValueTuple<string, string>, string> _normalizedPathsCache;
+        private readonly ConcurrentCache<(string, string), string> _normalizedPathsCache;
         private readonly SourceReferenceResolver _resolverOpt;
         private ImmutableArray<Cci.DebugSourceDocument> _embeddedDocuments;
 
@@ -30,7 +30,7 @@ public DebugDocumentsBuilder(SourceReferenceResolver resolverOpt, bool isDocumen
                     StringComparer.Ordinal :
                     StringComparer.OrdinalIgnoreCase);
 
-            _normalizedPathsCache = new ConcurrentCache<ValueTuple<string, string>, string>(16);
+            _normalizedPathsCache = new ConcurrentCache<(string, string), string>(16);
             _embeddedDocuments = ImmutableArray<Cci.DebugSourceDocument>.Empty;
         }
 
@@ -71,7 +71,7 @@ internal string NormalizeDebugDocumentPath(string path, string basePath)
                 return path;
             }
 
-            var key = ValueTuple.Create(path, basePath);
+            var key = (path, basePath);
             string normalizedPath;
             if (!_normalizedPathsCache.TryGetValue(key, out normalizedPath))
             {

src/Compilers/Core/Portable/InternalUtilities/ValueTuple.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-namespace Roslyn.Utilities
-{
-    // tuple factory
-    internal static class ValueTuple
-    {
-        public static ValueTuple<T1, T2> Create<T1, T2>(T1 item1, T2 item2)
-        {
-            return new ValueTuple<T1, T2>(item1, item2);
-        }
-
-        public static ValueTuple<T1, T2, T3> Create<T1, T2, T3>(T1 item1, T2 item2, T3 item3)
-        {
-            return new ValueTuple<T1, T2, T3>(item1, item2, item3);
-        }
-    }
-}

src/Compilers/Core/Portable/InternalUtilities/ValueTuple`2.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-
-namespace Roslyn.Utilities
-{
-    // struct with two values
-    internal struct ValueTuple<T1, T2> : IEquatable<ValueTuple<T1, T2>>
-    {
-        private static readonly EqualityComparer<T1> s_comparer1 = EqualityComparer<T1>.Default;
-        private static readonly EqualityComparer<T2> s_comparer2 = EqualityComparer<T2>.Default;
-
-        public readonly T1 Item1;
-        public readonly T2 Item2;
-
-        public ValueTuple(T1 item1, T2 item2)
-        {
-            this.Item1 = item1;
-            this.Item2 = item2;
-        }
-
-        public bool Equals(ValueTuple<T1, T2> other)
-        {
-            return s_comparer1.Equals(this.Item1, other.Item1)
-                && s_comparer2.Equals(this.Item2, other.Item2);
-        }
-
-        public override bool Equals(object obj)
-        {
-            if (obj is ValueTuple<T1, T2>)
-            {
-                var other = (ValueTuple<T1, T2>)obj;
-                return this.Equals(other);
-            }
-
-            return false;
-        }
-
-        public override int GetHashCode()
-        {
-            return Hash.Combine(s_comparer1.GetHashCode(Item1), s_comparer2.GetHashCode(Item2));
-        }
-
-        public static bool operator ==(ValueTuple<T1, T2> left, ValueTuple<T1, T2> right)
-        {
-            return left.Equals(right);
-        }
-
-        public static bool operator !=(ValueTuple<T1, T2> left, ValueTuple<T1, T2> right)
-        {
-            return !left.Equals(right);
-        }
-    }
-}

src/Compilers/Core/Portable/InternalUtilities/ValueTuple`3.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-
-namespace Roslyn.Utilities
-{
-    // struct with three values
-    internal struct ValueTuple<T1, T2, T3> : IEquatable<ValueTuple<T1, T2, T3>>
-    {
-        private static readonly EqualityComparer<T1> s_comparer1 = EqualityComparer<T1>.Default;
-        private static readonly EqualityComparer<T2> s_comparer2 = EqualityComparer<T2>.Default;
-        private static readonly EqualityComparer<T3> s_comparer3 = EqualityComparer<T3>.Default;
-
-        public readonly T1 Item1;
-        public readonly T2 Item2;
-        public readonly T3 Item3;
-
-        public ValueTuple(T1 item1, T2 item2, T3 item3)
-        {
-            this.Item1 = item1;
-            this.Item2 = item2;
-            this.Item3 = item3;
-        }
-
-        public bool Equals(ValueTuple<T1, T2, T3> other)
-        {
-            return s_comparer1.Equals(this.Item1, other.Item1)
-                && s_comparer2.Equals(this.Item2, other.Item2)
-                && s_comparer3.Equals(this.Item3, other.Item3);
-        }
-
-        public override bool Equals(object obj)
-        {
-            if (obj is ValueTuple<T1, T2, T3>)
-            {
-                var other = (ValueTuple<T1, T2, T3>)obj;
-                return this.Equals(other);
-            }
-
-            return false;
-        }
-
-        public override int GetHashCode()
-        {
-            return Hash.Combine(
-                Hash.Combine(
-                    s_comparer1.GetHashCode(Item1),
-                    s_comparer2.GetHashCode(Item2)),
-                s_comparer3.GetHashCode(Item3));
-        }
-
-        public static bool operator ==(ValueTuple<T1, T2, T3> left, ValueTuple<T1, T2, T3> right)
-        {
-            return left.Equals(right);
-        }
-
-        public static bool operator !=(ValueTuple<T1, T2, T3> left, ValueTuple<T1, T2, T3> right)
-        {
-            return !left.Equals(right);
-        }
-    }
-}

src/Compilers/Core/Portable/ReferenceManager/CommonReferenceManager.Binding.cs

@@ -230,7 +230,7 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol>
             Dictionary<MetadataReference, MergedAliases> lazyAliasMap = null;
 
             // metadata references and corresponding bindings of their references, used to calculate a fixed point:
-            var referenceBindingsToProcess = ArrayBuilder<ValueTuple<MetadataReference, ArraySegment<AssemblyReferenceBinding>>>.GetInstance();
+            var referenceBindingsToProcess = ArrayBuilder<(MetadataReference, ArraySegment<AssemblyReferenceBinding>)>.GetInstance();
 
             // collect all missing identities, resolve the assemblies and bind their references against explicit definitions:
             GetInitialReferenceBindingsToProcess(explicitModules, explicitReferences, explicitReferenceMap, referenceBindings, totalReferencedAssemblyCount, referenceBindingsToProcess);
@@ -296,7 +296,7 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol>
 
                         var referenceBinding = data.BindAssemblyReferences(explicitAssemblies, IdentityComparer);
                         referenceBindings.Add(referenceBinding);
-                        referenceBindingsToProcess.Push(ValueTuple.Create((MetadataReference)resolvedReference, new ArraySegment<AssemblyReferenceBinding>(referenceBinding)));
+                        referenceBindingsToProcess.Push((resolvedReference, new ArraySegment<AssemblyReferenceBinding>(referenceBinding)));
                     }
                 }
 
@@ -361,7 +361,7 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol>
             ImmutableArray<ResolvedReference> explicitReferenceMap,
             ArrayBuilder<AssemblyReferenceBinding[]> referenceBindings,
             int totalReferencedAssemblyCount,
-            [Out]ArrayBuilder<ValueTuple<MetadataReference, ArraySegment<AssemblyReferenceBinding>>> result)
+            [Out]ArrayBuilder<(MetadataReference, ArraySegment<AssemblyReferenceBinding>)> result)
         {
             Debug.Assert(result.Count == 0);
 
@@ -376,9 +376,9 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol>
                 var moduleReference = explicitReferences[explicitModuleToReferenceMap[moduleIndex]];
                 var moduleBindingsCount = explicitModules[moduleIndex].ReferencedAssemblies.Length;
 
-                result.Add(ValueTuple.Create(
-                    moduleReference,
-                    new ArraySegment<AssemblyReferenceBinding>(bindingsOfAssemblyBeingBuilt, bindingIndex, moduleBindingsCount)));
+                result.Add(
+                    (moduleReference,
+                     new ArraySegment<AssemblyReferenceBinding>(bindingsOfAssemblyBeingBuilt, bindingIndex, moduleBindingsCount)));
 
                 bindingIndex += moduleBindingsCount;
             }
@@ -395,9 +395,9 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol>
                 }
 
                 // +1 for the assembly being built
-                result.Add(ValueTuple.Create(
-                    explicitReferences[referenceIndex],
-                    new ArraySegment<AssemblyReferenceBinding>(referenceBindings[explicitReferenceMapping.Index + 1])));
+                result.Add(
+                    (explicitReferences[referenceIndex],
+                     new ArraySegment<AssemblyReferenceBinding>(referenceBindings[explicitReferenceMapping.Index + 1])));
             }
 
             // we have a reference binding for each module and for each referenced assembly:

src/Compilers/Core/Portable/ReferenceManager/CommonReferenceManager.Resolution.cs

@@ -194,7 +194,7 @@ public ReferencedAssemblyIdentity(AssemblyIdentity identity, MetadataReference r
             TCompilation compilation,
             [Out] Dictionary<string, List<ReferencedAssemblyIdentity>> assemblyReferencesBySimpleName,
             out ImmutableArray<MetadataReference> references,
-            out IDictionary<ValueTuple<string, string>, MetadataReference> boundReferenceDirectiveMap,
+            out IDictionary<(string, string), MetadataReference> boundReferenceDirectiveMap,
             out ImmutableArray<MetadataReference> boundReferenceDirectives,
             out ImmutableArray<AssemblyData> assemblies,
             out ImmutableArray<PEModule> modules,
@@ -746,7 +746,7 @@ private static void AddModule(PEModule module, int referenceIndex, ResolvedRefer
             TCompilation compilation,
             DiagnosticBag diagnostics,
             out ImmutableArray<MetadataReference> references,
-            out IDictionary<ValueTuple<string, string>, MetadataReference> boundReferenceDirectives,
+            out IDictionary<(string, string), MetadataReference> boundReferenceDirectives,
             out ImmutableArray<Location> referenceDirectiveLocations)
         {
             boundReferenceDirectives = null;
@@ -765,7 +765,7 @@ private static void AddModule(PEModule module, int referenceIndex, ResolvedRefer
                     }
 
                     // we already successfully bound #r with the same value:
-                    if (boundReferenceDirectives != null && boundReferenceDirectives.ContainsKey(ValueTuple.Create(referenceDirective.Location.SourceTree.FilePath, referenceDirective.File)))
+                    if (boundReferenceDirectives != null && boundReferenceDirectives.ContainsKey((referenceDirective.Location.SourceTree.FilePath, referenceDirective.File)))
                     {
                         continue;
                     }
@@ -779,13 +779,13 @@ private static void AddModule(PEModule module, int referenceIndex, ResolvedRefer
 
                     if (boundReferenceDirectives == null)
                     {
-                        boundReferenceDirectives = new Dictionary<ValueTuple<string, string>, MetadataReference>();
+                        boundReferenceDirectives = new Dictionary<(string, string), MetadataReference>();
                         referenceDirectiveLocationsBuilder = ArrayBuilder<Location>.GetInstance();
                     }
 
                     referencesBuilder.Add(boundReference);
                     referenceDirectiveLocationsBuilder.Add(referenceDirective.Location);
-                    boundReferenceDirectives.Add(ValueTuple.Create(referenceDirective.Location.SourceTree.FilePath, referenceDirective.File), boundReference);
+                    boundReferenceDirectives.Add((referenceDirective.Location.SourceTree.FilePath, referenceDirective.File), boundReference);
                 }
 
                 // add external reference at the end, so that they are processed first:
@@ -801,7 +801,7 @@ private static void AddModule(PEModule module, int referenceIndex, ResolvedRefer
                 if (boundReferenceDirectives == null)
                 {
                     // no directive references resolved successfully:
-                    boundReferenceDirectives = SpecializedCollections.EmptyDictionary<ValueTuple<string, string>, MetadataReference>();
+                    boundReferenceDirectives = SpecializedCollections.EmptyDictionary<(string, string), MetadataReference>();
                 }
 
                 references = referencesBuilder.ToImmutable();

src/Compilers/Core/Portable/ReferenceManager/CommonReferenceManager.State.cs

@@ -36,7 +36,7 @@ internal abstract class CommonReferenceManager
         /// <summary>
         /// Enumerates all referenced assemblies and their aliases.
         /// </summary>
-        internal abstract IEnumerable<ValueTuple<IAssemblySymbol, ImmutableArray<string>>> GetReferencedAssemblyAliases();
+        internal abstract IEnumerable<(IAssemblySymbol, ImmutableArray<string>)> GetReferencedAssemblyAliases();
 
         internal abstract MetadataReference GetMetadataReference(IAssemblySymbol assemblySymbol);
         internal abstract ImmutableArray<MetadataReference> ExplicitReferences { get; }
@@ -100,7 +100,7 @@ internal partial class CommonReferenceManager<TCompilation, TAssemblySymbol> : C
         /// Maps (containing syntax tree file name, reference string) of #r directive to a resolved metadata reference.
         /// If multiple #r's in the same tree use the same value as a reference the resolved metadata reference is the same as well.
         /// </summary>
-        private IDictionary<ValueTuple<string, string>, MetadataReference> _lazyReferenceDirectiveMap;
+        private IDictionary<(string, string), MetadataReference> _lazyReferenceDirectiveMap;
 
         /// <summary>
         /// Array of unique bound #r references.
@@ -216,7 +216,7 @@ internal bool HasCircularReference
             }
         }
 
-        internal IDictionary<ValueTuple<string, string>, MetadataReference> ReferenceDirectiveMap
+        internal IDictionary<(string, string), MetadataReference> ReferenceDirectiveMap
         {
             get
             {
@@ -373,7 +373,7 @@ internal bool IsBound
         internal void InitializeNoLock(
             Dictionary<MetadataReference, int> referencedAssembliesMap,
             Dictionary<MetadataReference, int> referencedModulesMap,
-            IDictionary<ValueTuple<string, string>, MetadataReference> boundReferenceDirectiveMap,
+            IDictionary<(string, string), MetadataReference> boundReferenceDirectiveMap,
             ImmutableArray<MetadataReference> directiveReferences,
             ImmutableArray<MetadataReference> explicitReferences,
             ImmutableArray<MetadataReference> implicitReferences,
@@ -662,11 +662,11 @@ internal override MetadataReference GetMetadataReference(IAssemblySymbol assembl
             return null;
         }
 
-        internal override IEnumerable<ValueTuple<IAssemblySymbol, ImmutableArray<string>>> GetReferencedAssemblyAliases()
+        internal override IEnumerable<(IAssemblySymbol, ImmutableArray<string>)> GetReferencedAssemblyAliases()
         {
             for (int i = 0; i < ReferencedAssemblies.Length; i++)
             {
-                yield return ValueTuple.Create((IAssemblySymbol)ReferencedAssemblies[i], AliasesOfReferencedAssemblies[i]);
+                yield return ((IAssemblySymbol)ReferencedAssemblies[i], AliasesOfReferencedAssemblies[i]);
             }
         }
 

src/Compilers/Core/Portable/Syntax/GreenNode.cs

@@ -646,15 +646,16 @@ public void WriteTo(System.IO.TextWriter writer)
         protected internal void WriteTo(TextWriter writer, bool leading, bool trailing)
         {
             // Use an actual Stack so we can write out deeply recursive structures without overflowing.
-            var stack = new Stack<ValueTuple<GreenNode, bool, bool>>();
-            stack.Push(ValueTuple.Create(this, leading, trailing));
+            var stack = new Stack<(GreenNode node, bool leading, bool trailing)>();
+            stack.Push((this, leading, trailing));
 
             // Separated out stack processing logic so that it does not unintentially refer to 
             // "this", "leading" or "trailing.
             ProcessStack(writer, stack);
         }
 
-        private static void ProcessStack(TextWriter writer, Stack<ValueTuple<GreenNode, bool, bool>> stack)
+        private static void ProcessStack(TextWriter writer,
+            Stack<(GreenNode node, bool leading, bool trailing)> stack)
         {
             while (stack.Count > 0)
             {
@@ -685,7 +686,7 @@ private static void ProcessStack(TextWriter writer, Stack<ValueTuple<GreenNode,
                     {
                         var first = i == firstIndex;
                         var last = i == lastIndex;
-                        stack.Push(ValueTuple.Create(child, currentLeading | !first, currentTrailing | !last));
+                        stack.Push((child, currentLeading | !first, currentTrailing | !last));
                     }
                 }
             }

src/Compilers/Core/Portable/project.json

@@ -20,6 +20,7 @@
     "System.Text.Encoding": "4.0.11",
     "System.Text.Encoding.CodePages": "4.0.1",
     "System.Text.Encoding.Extensions": "4.0.11",
+    "System.ValueTuple": "4.0.1-beta-24425-02",
     "System.Xml.ReaderWriter": "4.0.11",
     "System.Xml.XDocument": "4.0.11",
     "System.Xml.XmlDocument": "4.0.1",

src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb

@@ -1191,7 +1191,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
 
-        Friend Overrides ReadOnly Property ReferenceDirectiveMap As IDictionary(Of ValueTuple(Of String, String), MetadataReference)
+        Friend Overrides ReadOnly Property ReferenceDirectiveMap As IDictionary(Of (path As String, content As String), MetadataReference)
             Get
                 Return GetBoundReferenceManager().ReferenceDirectiveMap
             End Get

src/EditorFeatures/Core/Implementation/NavigationBar/NavigationBarController_ModelComputation.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/Features/CSharp/Portable/Completion/CompletionProviders/ObjectCreationCompletionProvider.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;

src/Features/CSharp/Portable/Completion/CompletionProviders/PartialTypeCompletionProvider.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;

src/Features/Core/Portable/Completion/Providers/AbstractObjectCreationCompletionProvider.cs

@@ -12,6 +12,7 @@
 using Microsoft.CodeAnalysis.Shared.Extensions.ContextQuery;
 using Roslyn.Utilities;
 using Microsoft.CodeAnalysis.Shared.Utilities;
+using System;
 
 namespace Microsoft.CodeAnalysis.Completion.Providers
 {

src/Features/Core/Portable/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.InMemoryStorage.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Immutable;
 using Roslyn.Utilities;

src/Features/Core/Portable/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateSet.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;

src/Features/Core/Portable/EditAndContinue/EncEditSessionInfo.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using Roslyn.Utilities;
 

src/Test/Utilities/Shared/MarkedSource/SourceWithMarkedNodes.cs

@@ -28,7 +28,7 @@ public SourceWithMarkedNodes(string markedSource, Func<string, SyntaxTree> parse
             SpansAndKindsAndIds = ImmutableArray.CreateRange(GetSpansRecursive(markedSource, 0, getSyntaxKind));
         }
 
-        private static IEnumerable<ValueTuple<TextSpan, int, int>> GetSpansRecursive(string markedSource, int offset, Func<string, int> getSyntaxKind)
+        private static IEnumerable<(TextSpan, int, int)> GetSpansRecursive(string markedSource, int offset, Func<string, int> getSyntaxKind)
         {
             foreach (var match in s_markerPattern.Matches(markedSource).ToEnumerable())
             {
@@ -38,7 +38,7 @@ public SourceWithMarkedNodes(string markedSource, Func<string, SyntaxTree> parse
                 var parsedKind = string.IsNullOrEmpty(syntaxKindOpt) ? 0 : getSyntaxKind(syntaxKindOpt);
                 int absoluteOffset = offset + markedSyntax.Index;
 
-                yield return ValueTuple.Create(new TextSpan(absoluteOffset, markedSyntax.Length), parsedKind, id);
+                yield return (new TextSpan(absoluteOffset, markedSyntax.Length), parsedKind, id);
 
                 foreach (var nestedSpan in GetSpansRecursive(markedSyntax.Value, absoluteOffset, getSyntaxKind))
                 {

src/VisualStudio/Core/Def/Implementation/EditAndContinue/DebugLogMessage.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/VisualStudio/Core/Def/Implementation/Library/FindResults/LibraryManager_FindReferences.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;

src/Workspaces/CSharp/Portable/Formatting/Engine/AggregatedFormattingResult.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/Workspaces/CSharp/Portable/Formatting/Engine/Trivia/TriviaDataFactory.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Diagnostics;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;

src/Workspaces/CSharp/Portable/Formatting/Engine/Trivia/TriviaRewriter.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/Workspaces/CSharp/Portable/Formatting/Rules/IndentBlockFormattingRule.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Composition;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -204,7 +205,7 @@ private void AddBlockIndentationOperation(List<IndentBlockOperation> list, Synta
             AddIndentBlockOperation(list, bracePair.Item1.GetNextToken(includeZeroWidth: true), bracePair.Item2.GetPreviousToken(includeZeroWidth: true));
         }
 
-        private void AddAlignmentBlockOperationRelativeToFirstTokenOnBaseTokenLine(List<IndentBlockOperation> list, Roslyn.Utilities.ValueTuple<SyntaxToken, SyntaxToken> bracePair)
+        private void AddAlignmentBlockOperationRelativeToFirstTokenOnBaseTokenLine(List<IndentBlockOperation> list, ValueTuple<SyntaxToken, SyntaxToken> bracePair)
         {
             var option = IndentBlockOption.RelativeToFirstTokenOnBaseTokenLine;
             SetAlignmentBlockOperation(list, bracePair.Item1, bracePair.Item1.GetNextToken(includeZeroWidth: true), bracePair.Item2, option);

src/Workspaces/CSharp/Portable/Formatting/Rules/WrappingFormattingRule.cs

@@ -74,7 +74,7 @@ public override void AddSuppressOperations(List<SuppressOperation> list, SyntaxN
         private void AddSpecificNodesSuppressOperations(List<SuppressOperation> list, SyntaxNode node)
         {
             var tokens = GetSpecificNodeSuppressionTokenRange(node);
-            if (tokens != default(ValueTuple<SyntaxToken, SyntaxToken>))
+            if (!tokens.Equals(default(ValueTuple<SyntaxToken, SyntaxToken>)))
             {
                 AddSuppressWrappingIfOnSingleLineOperation(list, tokens.Item1, tokens.Item2);
             }
@@ -106,7 +106,7 @@ private void RemoveSuppressOperationForStatementMethodDeclaration(List<SuppressO
             }
 
             var tokens = GetSpecificNodeSuppressionTokenRange(node);
-            if (tokens != default(ValueTuple<SyntaxToken, SyntaxToken>))
+            if (!tokens.Equals(default(ValueTuple<SyntaxToken, SyntaxToken>)))
             {
                 RemoveSuppressOperation(list, tokens.Item1, tokens.Item2);
             }

src/Workspaces/Core/Portable/CodeGeneration/AbstractFlagsEnumGenerator.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.CodeAnalysis;

src/Workspaces/Core/Portable/Formatting/Engine/AbstractAggregatedFormattingResult.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/Workspaces/Core/Portable/Formatting/Engine/AbstractFormattingResult.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using Microsoft.CodeAnalysis.Internal.Log;

src/Workspaces/Core/Portable/SymbolKey/SymbolKey.BodyLevelSymbolKey.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;

src/Workspaces/Core/Portable/Workspace/Solution/SolutionState.CompilationTracker.State.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis;

src/Workspaces/Core/Portable/Workspaces.csproj

@@ -165,15 +165,6 @@
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\TextChangeRangeExtensions.cs">
       <Link>InternalUtilities\TextChangeRangeExtensions.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ValueTuple.cs">
-      <Link>InternalUtilities\ValueTuple.cs</Link>
-    </Compile>
-    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ValueTuple`2.cs">
-      <Link>InternalUtilities\ValueTuple`2.cs</Link>
-    </Compile>
-    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\ValueTuple`3.cs">
-      <Link>InternalUtilities\ValueTuple`3.cs</Link>
-    </Compile>
     <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\WeakReferenceExtensions.cs">
       <Link>InternalUtilities\WeakReferenceExtensions.cs</Link>
     </Compile>

src/Workspaces/Remote/Core/Services/AssetSource.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;

src/Workspaces/Remote/Core/Services/SolutionService.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;

src/Workspaces/Remote/ServiceHub/Services/SnapshotService.JsonRpcAssetSource.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;