CODEWITHSUNDEEP
c++templatesrandomvector
user2577345
user2577345

Reputation:

Function template isn't producing random numbers properly

I have a function template that is supposed to take a vector and produce random numbers inside it. However, when I print entire vector, it's all zeros.

code:

const  int smallSize = 20;

// declare small vector
vector <int> smallVector(smallSize);

genRand(smallVector, smallSize);

// make copy of small vector 
vector<int> copySmallVector = smallVector;

// function template for generating random numbers
template<class T, class B>void genRand(T data, B size)
{
    for (B i = 0; i < size; i++)
    {
        data[i] = (1 + rand() % size);
    }
}

Upvotes: 1

Views: 48

Answers (1)

Paul R
Paul R

Reputation: 213059

You are generating random numbers in a copy of your vector, and then throwing it away when the function returns.

Change:

template<class T, class B>void genRand(T data, B size)

to:

template<class T, class B>void genRand(T &data, B size)
                                       ^^^^^^^

Upvotes: 5

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