For example, as part of a container class:

void remove_memory_blocks(pointer back_element_in_final_block)
{
   if constexpr(!std::is_trivially_destructible<element_type>::value)
   {
      // destroy each element in each memory block until the back_element is reached
   }

   // remove memory blocks
}


If element_type is_trivially_destructible, G++ will warn that back_element_in_final_block is unused every time the function is called.

Ideally this warning should be performed before constexpr blocks are removed by a parser (I have no idea what the procedure is for GCC, I'm just guessing here)