Not facebook examples, but things I've seen are as follows. All these were fixable to be correct for both GCC and Clang (it's worth it for the clang static anal

Not facebook examples, but things I've seen are as follows. All these were fixable to be correct for both GCC and Clang (it's worth it for the clang static analysis). GCC can call the base destructor explicitly in destructors (an error in clang). i.e. this->~BaseClass(); This is normally a coding error anyway, since the call is added by the compiler. You sometimes have to add this-> in templates to disambiguate which function is called. GCC has, or had, a better (different?) two-phase look up for templates, so you can #include a file after its template is used in another header. Clang is stricter and requires you #include "A.h" and #include "foo.h" before using A<foo>, even if the overall compilation unit does eventually declare the A template and the foo class. GCC supports variable length arrays, so you can do `MyClass x[someValue + 1];`, but with Clang you need to use a vector of MyClass, like vector<MyClass> x(someValue + 1). This sort of thing compiles in GCC, but not clang: template <typename T> class List : public list<T> {}; const List<string> tmpList; It is missing a default constructor, GCC finds one from somewhere :) GCC allows friends of derived classes to call static base class protected functions. i.e. Base::protectedFunc() can be called if the current class is a friend only of BaseSubclass. In clang you need to call BaseSubclass::protectedFunc(). Clang requires more explicit template instantiation to avoid link errors. Not sure exactly when, just "sometimes" and you'll know it when you see it :-) Then as mentioned elsewhere clang shouts a lot about mismatched forward declaration (struct vs class).