Question

I tried using boost optional and it works nice, but I cant find a way to call the member functions of the wrapped type. Is that by design or? I guess so because calling member funcs of unitialized boost::optional variable would be bad, but I want to be 100% sure.

class test
{
    int test_method()
    {
        return 1984;
    }
};
test tst;
boost::optional<test> get_test()
{
    boost::optional<test> result(tst);
    return result;
}


// main

    boost::optional <test> ret_val= get_test();
    int x=ret_val.test_method();

‘class boost::optional ANGLE_BRACKET test ANGLE_BRACKET ’ has no member named ‘test_method’

Answer 1

Try using ret_val->test_method() instead; operator-> can access the contained object in a boost::optional. Note that you need to ensure that the optional is not empty before you do that.