compiler-warnings

While getting started with some VS2005-generated MFC code, I noticed it overrode a method with something like this: void OnDraw(CDC* /*pDC*/) { ... // TODO: Add your code here } So of course, as soon as I added something I realized I needed to un-comment the pDC formal argument in order to compile, but I'm confused as to how/why a C++ function can compile (with no warnings) when the formal argument only has a type and not a name: void foo(int) { int x = 3; } int main() { foo(5); return 0; } Shouldn't this generate at least a warning (with -Wall or /W4)? It doesn't seem to. Am I missing

Once in a while it's difficult to write C++ code that wouldn't emit warnings at all. Having warnings enabled is however a good idea. So it is often necessary to disable warnings around some specific construct and have them enables in all other pieces of code. I've seen two ways of doing that so far. The first one is to use #pragma warning( push ) and #pragma warning( pop ) : #pragma warning( push ) #pragma warning( disable: ThatWarning ) //code with ThatWarning here #pragma warning( pop ) The second is to use #pragma warning( default ) : #pragma warning( disable: ThatWarning ) //code with

struct SemanticDirection; fn main() {} warning: struct is never used: `SemanticDirection` --> src/main.rs:1:1 | 1 | struct SemanticDirection; | ^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: #[warn(dead_code)] on by default I will turn these warnings back on for anything serious, but I am just tinkering with the language and this is driving me bats. I tried adding #[allow(dead_code)] to my code, but that did not work. Arjan You can either: Add an allow attribute on a struct, module, function, etc.: #[allow(dead_code)] struct SemanticDirection; Add a crate-level allow attribute ; notice the ! : #![allow