Visibility of template specialization of C++ function

Question

Suppose I have fileA.h which declares a class classA with template function SomeFunc(). This function is implemented directly

Answer 1

Per the specs, your specialized function template should never be called outside fileA.C, unless you export the template definition, which no compiler (except Comeau) currently supports (or has it planned for the forseeable future).

On the other hand, once the function template is instantiated, there is a function visible to the compiler that is no longer a template. GCC may re-use this definition across different compiler units because the standard states that each template shall only be instantiated once for a given set of type arguments [temp.spec]. Still, since the template is not exported, this should be limited to the compilation unit.

I believe that GCC may expose a bug here in sharing its list of instantiated templates across compilation units. Normally, this is a reasonable optimization but it should take function specializations into account which it doesn't seem to do correctly.