Method SharedFromThisVBase

tests/test_smart_ptr.cpp:244–244

// Issue #865: shared_from_this doesn't work with virtual inheritance
struct SharedFromThisVBase : std::enable_shared_from_this<SharedFromThisVBase> {
    SharedFromThisVBase() = default;
    SharedFromThisVBase(const SharedFromThisVBase &) = default;
    virtual ~SharedFromThisVBase() = default;
};