char4 regular_vec = char4(1);
const char4 const_vec   = char4(2);

void fxn()
{
   PrintVector("regular_vec", regular_vec);  // builds clean
   PrintVector("const_vec",   const_vec);    // gets error diagnostic
}

    int count = c7x::element_count_of<T>::value;

% cl7x file.cpp
"file.cpp", line 10: error: class "c7x::element_count_of<const char4>" has no member "value"
          detected during instantiation of "void PrintVector(std::__2::string, T &) [with T=const char4]" at line 28
1 error detected in the compilation of "file.cpp".

>> Compilation failure