CODEWITHSUNDEEP
c++arraysc++11templatesnull
Schwiftyy
Schwiftyy

Reputation: 1

How to determine whether an index of an array of unknown type is empty?

template<typename K, typename V, int N>
    class KVList
    {
        int m_size;
        K m_key[N] = {};
        V m_value[N] = {};

    public:
        KVList& add(const K&, const V&)
        {
             //Check if index is empty or null
                    //Add key value pair
        }
    }

Hey guys,

I'm creating a templated class that has 3 template parameters. My question, as stated above, is how I can determine whether or not an array at certain indexes is NULL or has no user-defined value.

Currently passing these datatypes as template arguments:

w4::KVList<std::string, double, 5> x;
w4::KVList<std::string, std::string, 5> y;

I was thinking maybe something along the lines of type conversions to bool might help but I'm stuck.

How can I check if the index has a null value for occurrences KVList accepts different datatypes or classes than the ones specified above?

Upvotes: 0

Views: 218

Answers (1)

max66
max66

Reputation: 66200

I want to know whether or not the array index is not user-defined so I can add values at the index.

You could add a third C-style array of bool's

bool isSet[N] = {};

and set/unset the values when keys and values are set/unset.

Upvotes: 1

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