iox-#1394 Add null checks in storable_function

Signed-off-by: Matthias Killat <[email protected]>

iceoryx_hoofs/include/iceoryx_hoofs/internal/cxx/storable_function.inl

@@ -146,6 +146,7 @@ inline storable_function<Capacity, signature<ReturnType, Args...>>::~storable_fu
 template <uint64_t Capacity, typename ReturnType, typename... Args>
 inline ReturnType storable_function<Capacity, signature<ReturnType, Args...>>::operator()(Args... args) const noexcept
 {
+    cxx::Expects(m_callable != nullptr); // should not happen unless incorrectly used after move
     // AXIVION Next Construct AutosarC++19_03-M0.3.1: m_invoker is initialized in ctor or assignment,
     // can only be nullptr if this was moved from (calling operator() is illegal in this case)
     return m_invoker(m_callable, std::forward<Args>(args)...);
@@ -198,6 +199,7 @@ inline void storable_function<Capacity, signature<ReturnType, Args...>>::copy(co
 
     // AXIVION Next Construct AutosarC++19_03-M5.2.8: type erasure - conversion to compatible type
     const auto obj = static_cast<CallableType*>(src.m_callable);
+    cxx::Expects(obj != nullptr); // should not happen unless src is incorrectly used after move
 
     // AXIVION Next Construct AutosarC++19_03-A5.3.2: obj is guaranteed not to be
     // nullptr unless src was invalidated by move (illegal use of src)
@@ -221,6 +223,7 @@ inline void storable_function<Capacity, signature<ReturnType, Args...>>::move(st
 
     // AXIVION Next Construct AutosarC++19_03-M5.2.8: type erasure - conversion to compatible type
     const auto obj = static_cast<CallableType*>(src.m_callable);
+    cxx::Expects(obj != nullptr); // should not happen unless src is incorrectly used after move
 
     // AXIVION Next Construct AutosarC++19_03-A5.3.2: obj is guaranteed not to be nullptr
     // unless src was invalidated by move (illegal use of src)