It’s weird that no one has mentioned LINQBridge. This little awesome project is a backport of LINQ (IEnumerable, but without IQueryable) and its dependencies (Func, Action, etc) to .NET 2.0. And: If your project references LINQBridge during compilation, then it will bind to LINQBridge’s query operators; if it references System.Core during compilation, then it will … Read more
Clearly the machine code the JIT compiler can generate for the first case is much more efficient. One rule that really helps there is that an object can only be unboxed to a variable that has the same type as the boxed value. That allows the JIT compiler to generate very efficient code, no value … 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);
I am under the impression that there are not truly “unassigned” values allowed by the runtime. In particular that a reference type that is not initialized will always have a null value, never the value left over from a previous invocation of the method or random value. Is this correct? I note that no one … Read more
A garbage collection doesn’t just get rid of unreferenced objects, it also compacts the heap. That’s a very important optimization. It doesn’t just make memory usage more efficient (no unused holes), it makes the CPU cache much more efficient. The cache is a really big deal on modern processors, they are an easy order of … Read more
C# doesn’t allow structs to derive from classes Your statement is incorrect, hence your confusion. C# does allow structs to derive from classes. All structs derive from the same class, System.ValueType, which derives from System.Object. And all enums derive from System.Enum. UPDATE: There has been some confusion in some (now deleted) comments, which warrants clarification. … Read more
You are looking at the guy that made that choice. David Cutler and his team selected one megabyte as the default stack size. Nothing to do with .NET or C#, this was nailed down when they created Windows NT. One megabyte is what it picks when the EXE header of a program or the CreateThread() … Read more
Strings aren’t value types since they can be huge, and need to be stored on the heap. Value types are (in all implementations of the CLR as of yet) stored on the stack. Stack allocating strings would break all sorts of things: the stack is only 1MB for 32-bit and 4MB for 64-bit, you’d have … Read more
P7 and P8 are the important ones to find out where the P9 exception was raised. Use P4 to know what assembly to look for. Run ildasm.exe and open that assembly. File + Dump, tick the “Token values” checkbox, OK and save the .il file somewhere. Open the file in a text editor. P7 gives … Read more
The answer below the line was written in 2008. C# 7 introduced pattern matching, which has largely replaced the as operator, as you can now write: if (randomObject is TargetType tt) { // Use tt here } Note that tt is still in scope after this, but not definitely assigned. (It is definitely assigned within … Read more