Why does clang give a weak-vtable warning for a class with a virtual method outside the network?

Question

Object.hpp:

class Object { public: virtual ~Object(); }; 

Object.cpp:

 #include "Object.hpp" Object::~Object() { } 

Compile it:

 >clang++ -v clang version 3.9.0 (branches/release_39) Target: x86_64-pc-windows-msvc Thread model: posix >clang++ -Weverything -c Object.cpp In file included from Object.cpp:1: ./Object.hpp:1:7: warning: 'Object' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit [-Wweak-vtables] class Object ^ 1 warning generated. 

But the object has a virtual method out of turn, so why does Klang generate this warning?