New IStructuralEquatable, IStructuralComparable and StructuralComparisons

4 Jul 2009 1 mins .NET, C#, F#

.NET Framework 4 comes with (among others) with two new interfaces. IStructuralEquatable and IStructuralComparable. These are implemented (right now in Beta 1) by Array and Tuple(s).

With this new implementations and StructuralComparisons you can check arrays and tuples for structural equality (or compare these).

object[] o1 = new object[] { 1, "2" };
object[] o2 = new object[] { 1, "2" };
Console.WriteLine(o1.Equals(o2));
Console.WriteLine(o1.Equals(o2, StructuralComparisons.StructuralEqualityComparer));

The code above writes first false and then true. The first one is classic “old-school” Equals. Following line is using new structural comparison, thus the true as result. Neat, isn’t it?

By the way, F# is now using these interfaces too.

Jiří Činčura is .NET, C# and Firebird expert. He focuses on data and business layers, language constructs, parallelism, databases and performance. For almost two decades he contributes to open-source, i.e. FirebirdClient. He works as a senior software engineer for Microsoft. Frequent speaker and blogger at www.tabsoverspaces.com.