C++ equivalent of C# default in generic code

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I have converted C# code to CLI/C++. I am facing one issue. There are some generics where default keyword is used.

public class GenericList
{
    public T GetNext()
    {
        T temp = default(T);
}

Here default keyword will return null for reference types and zero for numeric value types.

When I convert the code to C++, I am not able to find equivalent construct which can be used to replace it. What can be done here?

[edit]Code block added to preserve formatting - OriginalGriff[/edit]

Posted 11-Feb-11 21:25pm

Rajesh G Manwani from Mumbai

Updated 11-Feb-11 21:33pm

OriginalGriff

v2

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Sergey Alexandrovich Kryukov 12-Feb-11 23:06pm

Good question, my 5.
--SA

2 solutions

Solution 1

Since there is no equivalent in C++, you must use something different. This can help:
http://stackoverflow.com/questions/3693363/cs-default-keyword-equivalent-in-c[^]

Posted 11-Feb-11 22:20pm

Olivier Levrey

Comments

Sergey Alexandrovich Kryukov 12-Feb-11 22:29pm

There is more in-depth explanation here, my 5.
--SA

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Nish Nishant · Accepted Answer · 2011-02-12T04:41:00

Solution 2

I believe you were asking about the equivalent C++/CLI syntax, if so here goes:

MC++

generic<typename T> ref class GenericList
{
public:
    T GetNext()
    {
        T temp = T();
        return temp;
    }
};

In the above code snippet T() is identical to default(T) in C#, and will generate the exact same msil.

Posted 12-Feb-11 4:41am

Nish Nishant

Updated 12-Feb-11 4:43am

v2

Comments

Abhinav S 12-Feb-11 10:45am

Wow. They have generics in C++?
5.

Nish Nishant 12-Feb-11 10:46am

In C++/CLI, yes they do.

Abhinav S 12-Feb-11 10:46am

Ok I think I remembered them now (reading about templates). Never used them though.

Nish Nishant 12-Feb-11 10:46am

Generics is available only in C++/CLI. Templates can be used in standard C++ as well as in C++/CLI.

Abhinav S 12-Feb-11 12:10pm

Oh I see. Thank you.

Sergey Alexandrovich Kryukov 12-Feb-11 22:26pm

How could you live without .NET templates I wonder? They are too fundamental.
Or this is only about C++/CLI?
--SA

Abhinav S 13-Feb-11 0:18am

This is only about C++/CLI. :)