Unique class type Id that is safe and holds across library boundaries

Question

I would appreciate any help as C++ is not my primary language.

I have a template class that is derived in multiple libraries. I am trying to figure out a way to uniq

Answer 1

As Paul Houx pointed out here, trick with returning an address of static method may not work due to compiler optimizations. But we can make a workaround using __FILE__ and __LINE__ macros + volatile keyword.

The final solution will look something like this:

#define GET_TYPE_ID static size_t GetTypeId()   \
{                                               \
    volatile const char* file = __FILE__;       \
    volatile uint32_t line = __LINE__;          \
    return (size_t)&GetTypeId;                  \
}

class ClassA
{
public:
    GET_TYPE_ID
};

class ClassB
{
public:
    GET_TYPE_ID
};