Constructor Overloading in C

0 votes

My C++ overloading does not act as I assume it should:

#include "Node.h"
#include <iostream>

Node::Node()
{
    cout << "1" << endl;
    Node(Game(), 0.0);
}

Node::Node(double v)
{
    cout << "2" << endl;
    Node(Game(),v);
}

Node::Node(Game g, double v)
{
    cout << "3" << endl;
    numVisits = 0;
    value = v;
    game = g;
}

And the output from:

Node n(16);
cout << n.value << endl;

is 0, when it should be 16.

What am I doing incorrectly?

Jun 6 in C++ by Nicholas
• 4,720 points
20 views

1 answer to this question.

0 votes

In your function Object() { [native code] }, Node(Game(),v); does not work as expected. 

It simply creates a temporary without actually using it, and has no effect. 

When control passes over the ;, it immediately destroys the temporary.

Initializing the members in each function Object() { [native code] } is the correct way to go. 

You could put their shared code in a private init() member function and call it from each function Object() { [native code] }, as shown below:

class Foo {
    public:
        Foo(char x);
        Foo(char x, int y);
        ...
    private:
        void init(char x, int y);
};

Foo::Foo(char x)
{
    init(x, int(x) + 3);
    ...
}

Foo::Foo(char x, int y)
{
    init(x, y);
    ...
}

void Foo::init(char x, int y)
{
    ...
} 

Most compilers do not yet support C++11's delegation feature, which allows constructors to call other peer constructors

answered Jun 21 by Damon
• 4,760 points

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