Optional arguments are “sort-of” CLS-compliant. Methods with optional arguments are legal and can be successfully compiled with the CLSCompliant attribute, but callers of those methods don’t necessarily need to take account of the default parameter values or the optional attribute. (In which case those methods would behave in exactly the same way as standard methods, … Read more
Visual Studio adds a directive for the compiler, and the compiler checks the code for some more strict rules than in the native programming language. You can add the CLS compliant attribute to all your project by adding the assembly level attribute [assembly: CLSCompliant(true)] anywhere in your project, generally in the assemblyinfo.cs file. If the … Read more
You probably have [assembly:CLSCompliant(true)] somewhere in that specific project. This triggers the compiler to check all types to be CLS compliant. You can override this for a type or method or something with [CLSCompliant(false)].
From the Common Language Specification: CLS-compliant language compilers must follow the rules of Annex 7 of Technical Report 15 of the Unicode Standard 3.0, which governs the set of characters that can start and be included in identifiers. This standard is available from the Web site of the Unicode Consortium. If you look this up: … Read more
If you write a library or framework it makes sense to ensure your library can be used from any CLR language.
Not all languages have the concept of unsigned ints. For example VB 6 had no concept of unsigned ints which I suspect drove the decision of the designers of VB7/7.1 not to implement as well (it’s implemented now in VB8). To quote: http://msdn.microsoft.com/en-us/library/12a7a7h3.aspx The CLS was designed to be large enough to include the language … Read more
You mark classes with the CLSCompliant attribute when you want to make sure it can be used by any other .NET language. These are the basic rules: Unsigned types should not be part of the public interface of the class. What this means is public fields should not have unsigned types like uint or ulong, … Read more
Changing a method signature Kind: Binary-level Break Languages affected: C# (VB and F# most likely, but untested) API before change public static class Foo { public static void bar(int i); } API after change public static class Foo { public static bool bar(int i); } Sample client code working before change Foo.bar(13);