Method overloading (C# Specification Part 9)

Method overloading permits multiple methods in the same class to have the same name as long as they have unique signatures. When compiling an invocation of an overloaded method, the compiler uses overload resolution to determine the specific method to invoke. Overload resolution finds the one method that best matches the arguments or reports an error if no single best match can be found. The following example shows overload resolution in effect. The comment for each invocation in the Main method shows which method is actually invoked.

class Test
{
      static void F() {
            Console.WriteLine("F()");
      }

      static void F(object x) {
            Console.WriteLine("F(object)");
      }

      static void F(int x) {
            Console.WriteLine("F(int)");
      }

      static void F(double x) {
            Console.WriteLine("F(double)");
      }

      static void F<T>(T x) {
            Console.WriteLine("F<T>(T)");
      }

      static void F(double x, double y) {
            Console.WriteLine("F(double, double)");
      }

      static void Main() {
            F();                          // Invokes F()
            F(1);                         // Invokes F(int)
            F(1.0);                       // Invokes F(double)
            F("abc");               // Invokes F(object)
            F((double)1);           // Invokes F(double)
            F((object)1);           // Invokes F(object)
            F<int>(1);              // Invokes F<T>(T)
            F(1, 1);                      // Invokes F(double, double) }
}

As shown by the example, a particular method can always be selected by explicitly casting the arguments to the exact parameter types and/or explicitly supplying type arguments.

Comments

gcAllowVeryLargeObjects Element

There are numerous new features coming with .NET 4.5 and here, on this blog, you can find several posts about it. But the feature we are goint to talk about today is very exciting, because we were waiting for it more than 10 years. Since .NET 1.0 the memory limit of .NET object is 2GB. This means you cannot for example create array which contains elements with more than 2GB in total. If try to create such array, you will get the OutOfMemoryException. Let’s see an example how to produce OutOfMemoryException. Before that Open Visual Studio 2012, and create C# Console Application, like picture below. First lets create simple struct with two double members like example below: 1 2 3 4 5 6 7 8 9 10 11 12 public struct ComplexNumber { public double Re; public double Im; public ComplexNumber( double re, double im) { Re=re; Im=im; } } As we know this structure consumes about 16

Support for debugging lambda expressions with Visual Studio 2015

Anyone who uses LINQ (or lambdas in general) and the debugger will quickly discover the dreaded message “Expression cannot contain lambda expressions”. Lack of lambda support has been a limitation of the Visual Studio Debugger ever since Lambdas were added to C# and Visual Basic. With visual studio 2015 Microsoft has added support for debugging lambda expressions. Let’s first look at an example, and then I’ll walk you through current limitations. Example To try this yourself, create a new C# Console app with this code: using System.Diagnostics; using System.Linq; class Program { static void Main() { float[] values = Enumerable.Range(0, 100).Select(i => (float)i / 10).ToArray(); Debugger.Break(); } } Then compile, start debugging, and add “values.Where(v => (int)v == 3).ToArray()” in the Watch window. You’ll be happy to see the same as what the screenshot above shows you. I am using Visual Studio 2015 Preview and it has some limitations.

How to allow a very large object in .net application?

Since .NET 1.0 the memory limit of .NET object is 2GB. This means you cannot for example create array which contains elements with more than 2GB in total. If try to create such array, you will get the OutOfMemoryException. Let’s see an example how to produce OutOfMemoryException. Before that Open Visual Studio, and create C# Console Application. Lets create simple struct with two double members like example below: public struct ComplexNumber { public double Re; public double Im; public ComplexNumber(double re, double im) { Re = re; Im = im; } } As we know this structure consumes about 16 bytes of memory. So if we want to create array of this type which consume more than 2GB we need to create array at least with 134217728 instances. So this sample program below creates 130000000 (about 1,97 GB) of array. int maxCount = 130000000; ComplexNumber[] arr = null; try { arr = new ComplexNumber[maxCount]; } catch (Exception ex) { Console.WriteLine(ex.Message); } So if we run t

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