unreachable-code

unreachable code is compile time error in languages like Java. But why it is just warning in C++ & C? Consider following example: #include <iostream> int f() { int a=3; return a; int b=6; // oops it is unreachable code std::cout<<b; // program control never goes here } int main() { std::cout<<f()<<'\n'; } Shouldn't compiler throw an error in this program, because statements after return statements in function f() will never get executed? What is the reason for allowing unreachable code? bytecode77 Unreachable code is not a compile error in C++, but usually gives a warning, depending on your

I'm getting a "Unreachable code detected" message in Visual Studio at the point i++ in my code below. Can you spot what I've done wrong? try { RegistryKey OurKey = Registry.CurrentUser; OurKey.CreateSubKey("Software\\Resources\\Shared"); OurKey = OurKey.OpenSubKey("Software\\Resources\\Shared", true); for (int i = 0; i < cmbPaths.Items.Count; i++) //<---- problem with i { OurKey.SetValue("paths" + i, cmbPaths.Items[i]); break; } } The problem is that this actually isn't a loop. You don't have any condition on the break so you could equivalently write something like if(cmbPath.Items.Count > 0)

I get a whole lot of warnings about switches that only partially covers the range of an enumeration switched over. Therefor, I would like to have a "default" for all those switches and put __builtin_unreachable (GCC builtin) in that case, so that the compiler know that case is not reachable. However, I came to know that GCC4.3 does not support that builtin yet. Is there any good way to emulate that functionality? I thought about dereferencing a null pointer instead, but that may have other undesirable effects/warnings and such. Do you have any better idea? You can call an inline function

Sometimes when you are debugging, you have unreachable code fragment. Is there anyway to suppress the warning? The only way to do this on any compiler is @SuppressWarnings("all") . If you're using Eclipse, try @SuppressWarnings("unused") . Java has (primitive) support for debugging like this in that simple if on boolean constants will not generate such warnings (and, indeed when the evaluation is false the compiler will remove the entire conditioned block). So you can do: if(false) { // code you don't want to run } Likewise, if you are temporarily inserting an early termination for debugging,