gistfile1.txt

It seems to me you should at least be able to avoid figuring out all the different buffer offsets and field types.

maybe something like this?

    struct stuff_t
    {
    	std::uint16_t a;
    	float b;
    	std::uint64_t c;
    	// ...
    };
    
    template<typename Field>
    char const* copy_fild(Field& field, char const* pos)
    {
    	std::copy(pos, pos + sizeof(field), (char*)&field);
    	return pos + sizeof(field);
    }
    
    char const* copy_stuff(stuff_t& st, char const* const buffer)
    {
    	auto pos = buffer;
    
    	pos = copy_fild(st.a, pos);
    	pos = copy_fild(st.b, pos);
    	pos = copy_fild(st.c, pos);
    	// ...
    
    	return pos;
    }