I think the article Drill Into .NET Framework Internals to See How the CLR Creates Runtime Objects will answer your questions. In particular, see the section *Interface Vtable Map and Interface Map-, and the following section on Virtual Dispatch. It’s probably possible for the JIT compiler to figure things out and optimize the code for … Read more
If you really need synchronization of the rest of the constructor versus any threads which anyhow gets a reference to your not-yet-totally-constructed object, you can use a synchronized-block: public class Test { public Test() { final Test me = this; synchronized(this) { new Thread() { @Override public void run() { // … Reference ‘me,’ the … Read more
I end up having to remember what the macro is and substitute it in my head as I read. That seems to reflect poorly on the naming of the macros. I would assume you wouldn’t have to emulate the preprocessor if it were a log_function_entry() macro. The ones that I have encountered that were intuitive … Read more
You should use factors. Yes they can be a pain, but my theory is that 90% of why they’re a pain is because in read.table and read.csv, the argument stringsAsFactors = TRUE by default (and most users miss this subtlety). I say they are useful because model fitting packages like lme4 use factors and ordered … Read more
EDIT: Indeed there was a patch which included sign() in math, but it wasn’t accepted, because they didn’t agree on what it should return in all the edge cases (+/-0, +/-nan, etc) So they decided to implement only copysign, which (although more verbose) can be used to delegate to the end user the desired behavior … Read more
In addition to the other good answers, I’ll add yet another reason why to not put C-style constness into C#. You said: we mark parameter as const in order to be sure that its state will not be changed in method. If const actually did that, that would be great. Const doesn’t do that. The … Read more
UPDATE: This question was used as the inspiration for this blog post; see it for further details. http://ericlippert.com/2009/08/13/four-switch-oddities/ Thanks for the interesting question. There are a number of confusions and mis-statements in the various other answers, none of which actually explain why this is illegal. I shall attempt to be definitive. First off, to be … Read more
It’s an hairy question, but apparently the idea is that this hiding feature helps avoiding subtle bugs when making changes to a base class (that could otherwise “steal” calls that before would have been handled by the derived class). Still a change in a base class can influence the result of compilation of derived classes … Read more
I think it’s a poor judgement on part of C# architects. readonly modifier on local variables helps maintain program correctness (just like asserts) and can potentially help the compiler optimize code (at least in the case of other languages). The fact that it’s disallowed in C# right now, is another argument that some of the … Read more
Two things: Generally, Java has just 2 levels of scope: global and function. But, try/catch is an exception (no pun intended). When an exception is thrown and the exception object gets a variable assigned to it, that object variable is only available within the “catch” section and is destroyed as soon as the catch completes. … Read more