Csharp73 tuple equality

snippets/csharp/tuples/tuples/Person.cs

@@ -48,3 +48,76 @@ public static void Deconstruct(this Student s, out string first, out string last
     }
     #endregion
 }
+
+namespace TupleEquality
+{
+    public static class Tests
+    {
+        public static void EqualityTests()
+        {
+            Person nil = default;
+            Person blank = new Person(null, null);
+            Person sample = new Person("Bill", "Wagner");
+
+            Console.WriteLine("Starting Equality Tests");
+            Console.WriteLine($"nil equals nil: {nil == nil}");
+            Console.WriteLine($"nil equals blank: {nil == blank}");
+            Console.WriteLine($"nil equals sample: {nil == sample}");
+
+            Console.WriteLine($"blank equals nil: {blank == nil}");
+            Console.WriteLine($"blank equals blank: {blank == blank}");
+            Console.WriteLine($"blank equals sanple: {blank == sample}");
+
+            Console.WriteLine($"sample equals nil: {sample == nil}");
+            Console.WriteLine($"sample equals blank: {sample == blank}");
+            Console.WriteLine($"sample equals sanple: {sample == sample}");
+
+            Console.WriteLine($"nil not equals nil: {nil != nil}");
+            Console.WriteLine($"nil not equals blank: {nil != blank}");
+            Console.WriteLine($"nil not equals sample: {nil != sample}");
+
+            Console.WriteLine($"blank not equals nil: {blank != nil}");
+            Console.WriteLine($"blank not equals blank: {blank != blank}");
+            Console.WriteLine($"blank not equals sanple: {blank != sample}");
+
+            Console.WriteLine($"sample not equals nil: {sample != nil}");
+            Console.WriteLine($"sample not equals blank: {sample != blank}");
+            Console.WriteLine($"sample not equals sanple: {sample != sample}");
+
+        }
+    }
+    public class Person
+    {
+        public string FirstName { get; }
+        public string LastName { get; }
+
+        public Person(string first, string last)
+        {
+            FirstName = first;
+            LastName = last;
+        }
+
+        public void Deconstruct(out string firstName, out string lastName)
+        {
+            firstName = FirstName;
+            lastName = LastName;
+        }
+
+        // <SnippetEqualityTests>
+        public override bool Equals(object other) =>
+            (other is Person p) 
+            ? (FirstName, LastName) == (p.FirstName, p.LastName) 
+            : false;
+
+        public static bool operator ==(Person left, Person right) => 
+            (object.ReferenceEquals(left, null)) 
+            ? (object.ReferenceEquals(right, null)) 
+            : left.Equals(right);
+
+        public static bool operator !=(Person left, Person right) => !(left == right);
+        public override int GetHashCode() => (LastName, FirstName).GetHashCode();
+        // </SnippetEqualityTests>
+
+    }
+
+}

snippets/csharp/tuples/tuples/Program.cs

@@ -14,7 +14,7 @@ static void Main(string[] args)
 
             AssignmentStatements();
 
-            var sample = new List<double>{ 2.0, 4.0, 6.0, 8.0 };
+            var sample = new List<double> { 2.0, 4.0, 6.0, 8.0 };
 
             Console.WriteLine(StatisticsVersionOne.StandardDeviation(sample));
 
@@ -43,6 +43,69 @@ static void Main(string[] args)
 
             FunWithProjections();
 
+            // Declare different members and tuples:
+
+            SimpleTupleEquality();
+            NullableTupleEquality();
+            MemberConversions();
+            MemberNameConversions();
+
+            TupleEquality.Tests.EqualityTests();
+        }
+
+        private static void SimpleTupleEquality()
+        {
+            // <SnippetEquality>
+            var left = (a: 5, b: 10);
+            var right = (a: 5, b: 10);
+            Console.WriteLine(left == right); // displays 'true'
+            // </SnippetEquality>
+        }
+
+        private static void NullableTupleEquality()
+        {
+            // <SnippetNullableEquality>
+            var left = (a: 5, b: 10);
+            var right = (a: 5, b: 10);
+            (int a, int b)? nullableTuple = right;
+            Console.WriteLine(left == nullableTuple); // Also true
+            // </SnippetNullableEquality>
+        }
+
+        private static void MemberConversions()
+        {
+            // <SnippetMemberConversions>
+            // lifted conversions
+            var left = (a: 5, b: 10);
+            (int? a, int? b) nullableMembers = (5, 10);
+            Console.WriteLine(left == nullableMembers); // Also true
+
+            // converted type of left is (long, long)
+            (long a, long b) longTuple = (5, 10);
+            Console.WriteLine(left == longTuple); // Also true
+
+            // comparisons performed on (long, long) tuples
+            (long a, int b) longFirst = (5, 10);
+            (int a, long b) longSecond = (5, 10);
+            Console.WriteLine(longFirst == longSecond); // Also true
+            // </SnippetMemberConversions>
+        }
+
+        private static void MemberNameConversions()
+        { 
+            // <SnippetMemberNames>
+            (int a, string b) pair = (1, "Hello");
+            (int z, string y) another = (1, "Hello");
+            Console.WriteLine(pair == another); // true. Member names don't participate.
+            Console.WriteLine(pair == (z: 1, y: "Hello")); // warning: literal contains different member names
+            // </SnippetMemberNames>
+
+            //<SnippetNestedTuples>
+            (int, (int, int)) nestedTuple = (1, (2, 3));
+            Console.WriteLine(nestedTuple == (1, (2, 3)) );
+            // </SnippetNestedTuples>
+
+            // Value based equality tests (Person)
         }
 
         private static void FunWithProjections()
@@ -72,7 +135,7 @@ private static void FunWithProjections()
             Console.WriteLine(projections.Item2);
             // Accessing the third field:
             Console.WriteLine(projections.Item3);
-            // There is no semantic name 'Item`.
+            // There is no semantic name 'Item1`.
 
             var pt1 = (X: 3, Y: 0);
             var pt2 = (X: 3, Y: 4);

snippets/csharp/tuples/tuples/packages.config

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="System.ValueTuple" version="4.3.0-preview1-24530-04" targetFramework="net452" />
+  <package id="System.ValueTuple" version="4.5.0-rc1" targetFramework="net452" />
 </packages>

snippets/csharp/tuples/tuples/tuples.csproj

@@ -35,9 +35,8 @@
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Core" />
-    <Reference Include="System.ValueTuple, Version=4.0.1.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
-      <HintPath>..\packages\System.ValueTuple.4.3.0-preview1-24530-04\lib\netstandard1.0\System.ValueTuple.dll</HintPath>
-      <Private>True</Private>
+    <Reference Include="System.ValueTuple, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.ValueTuple.4.5.0-rc1\lib\netstandard1.0\System.ValueTuple.dll</HintPath>
     </Reference>
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />