C# Discussion Boards - CodeProject

13-Mar-13 6:35

I'm trying to override those operators:

XML

==, !=, <, >, <=, >=, <<, >>

...but VS10 give me this error:

Overloadable unary operator expected

Is there some special conditions to make this work..? Cause those operators are overloadable...

Eddy Vluggen13-Mar-13 6:37

Eddy Vluggen

13-Mar-13 6:37

Those are binary operators.

MSDN[^]

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If you can't read my code, try converting it here[^]

VendorX13-Mar-13 6:47

13-Mar-13 6:47

...and..? On MSDN they are overloadable...

Eddy Vluggen13-Mar-13 7:20

Eddy Vluggen

13-Mar-13 7:20

They're also overridable in your code. Did you check the example? There's a link at the bottom of the page.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

Dave Kreskowiak13-Mar-13 6:48

Dave Kreskowiak

13-Mar-13 6:48

And we'd need to see your code where you're overloading these operators to tell you what you're doing wrong.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Richard MacCutchan13-Mar-13 7:24

Richard MacCutchan

13-Mar-13 7:24

See http://msdn.microsoft.com/en-us/library/aa288467(v=vs.71).aspx[^].

Use the best guess

Pete O'Hanlon13-Mar-13 7:27

13-Mar-13 7:27

As Eddy states, those aren't Unary operators. This would indicate that these aren't the ones that are causing you problems. Could you post a sample that shows the code that the compiler is complaining about?

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VendorX13-Mar-13 7:49

13-Mar-13 7:49

OK, thanks guys for the links, but I've already seen this. Problem is that I'm trying to convert simple class from C++ to CS. Here is the code:

class SOME_API SomeClass
{
public:
    // Accessors.
    bool operator==( const SomeClass& Other ) const
    {
        return Index == Other.Index;
    }

    bool operator!=( const SomeClass& Other ) const
    {
        return Index != Other.Index;
    }

    //...

private:
    // SomeClass index.
    int Index;

    //...
};

Is there any chance to convert this to CS without writing a bunch of code?

DaveyM6913-Mar-13 9:02

DaveyM69

13-Mar-13 9:02

A rough untested example of how I do this for a class (it's much simpler for a struct as it can never be null):

// An immutable int wrapper class
public class SomeClass : IEquatable<SomeClass>
{
    private int index;

    public SomeClass(int index)
    {
        this.index = index;
    }

    public static bool operator ==(SomeClass instance, SomeClass other)
    {
        if(object.ReferenceEquals(instance, other))
            return true;
        if(object.ReferenceEquals(null, instance) || object.ReferenceEquals(null, other))
            return false;
        return instance.index == other.index;
    }
    public static bool operator !=(SomeClass instance, SomeClass other)
    {
        return !(instance == other);
    }

    public int Index
    {
        get { return index; }
    }

    public override bool Equals(object obj)
    {
        return Equals(obj as SomeClass);
    }
    public bool Equals(SomeClass other)
    {
        if(object.ReferenceEquals(null, other))
            return false;
        return index.Equals(other.index);
    }
    public override int GetHashCode()
    {
        return index;
    }
}

And a struct:

// An immutable int wrapper struct
public struct SomeStruct : IEquatable<SomeStruct>
{
    private int index;

    public SomeStruct(int index)
    {
        this.index = index;
    }

    public static bool operator ==(SomeStruct instance, SomeStruct other)
    {
        return instance.index == other.index;
    }
    public static bool operator !=(SomeStruct instance, SomeStruct other)
    {
        return !(instance == other);
    }

    public int Index
    {
        get { return index; }
    }

    public override bool Equals(object obj)
    {
        if(obj is SomeStruct)
            return Equals((SomeStruct)obj);
        return false;
    }
    public bool Equals(SomeStruct other)
    {
        return index.Equals(other.index);
    }
    public override int GetHashCode()
    {
        return index;
    }
}

Dave

Binging is like googling, it just feels dirtier.
Please take your VB.NET out of our nice case sensitive forum.
Astonish us. Be exceptional. (Pete O'Hanlon)

BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)

DaveyM6913-Mar-13 9:10

DaveyM69

13-Mar-13 9:10

Unary operators require one parameter, so it's assuming that the operator should be a unary one as you are only supplying one parameter.
The operators you have listed are binary operators, so require two parameters.

See my example in my other post and my article An Introduction to Operator Overloading in C#[^]

VendorX13-Mar-13 9:38

13-Mar-13 9:38

Thanks for the snippets DaveyM69 - I've ended up with something similar. For now, to compare I'm using GetIndex(), but my converted code is constantly growing. Didn't know that CS is so much more complicated...
Thanks again...

MicroVirus13-Mar-13 12:06

MicroVirus

13-Mar-13 12:06

I don't believe C# is much more complicated with this; I think the real difference is that you'd typically let the overloaded operators be member functions in C++ and C# wants them to be static functions. So if you rewrite your C++ code to the static overloading, then you're already having the same code in C# and C++.

Mdi form in c#

keyur_raval13-Mar-13 2:09

keyur_raval

13-Mar-13 2:09

Is that possible to open two mdi parent form in one(same) mdi container???? And if yes then how????

Please Give me the answer.......

Re: Mdi form in c#

Pete O'Hanlon13-Mar-13 2:17

How to record the video from a System.Windows.Forms.Panel?

13-Mar-13 2:17

keyur_raval wrote:
Is that possible to open two mdi parent form in one(same) mdi container

Not at the same time. You can change what the MDI Parent is, but you can't have two of them together.

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

makhondi13-Mar-13 1:33

makhondi

13-Mar-13 1:33

1.How to record the video from a System.Windows.Forms.Panel?

1.How to record the video from a System.Windows.Forms.Panel By Use Handle?

Re: How to record the video from a System.Windows.Forms.Panel?

NotPolitcallyCorrect13-Mar-13 1:43

NotPolitcallyCorrect

13-Mar-13 1:43

Your reposted question is no better phrased than the question you posted 34 minutes ago.

You should read this[^]

Re: How to record the video from a System.Windows.Forms.Panel?

makhondi13-Mar-13 1:50

makhondi

13-Mar-13 1:50

Please Write a better answer

Re: How to record the video from a System.Windows.Forms.Panel?

NotPolitcallyCorrect13-Mar-13 2:36

NotPolitcallyCorrect

13-Mar-13 2:36

makhondi wrote:
Please Write a better answer

As a general rule, the quality of the answer you get is directly proportional to the quality of the question asked. Take your question for example. It's vague, broad in scope, not even a question, demonstrates lack of any research, does not demonstrate any effort on your part and does not make any sense to begin with. As a result you are going to get vague, broad answers that are probably not going to be of much help.

Bottom line: you want better answers then ask better questions.

Re: How to record the video from a System.Windows.Forms.Panel?

Pete O'Hanlon13-Mar-13 2:08

Re: How to record the video from a System.Windows.Forms.Panel?

13-Mar-13 2:08

I'm confused about your question. You normally wouldn't use a panel to display video information, so how are you actually displaying the video there?

I was brought up to respect my elders. I don't respect many people nowadays.

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Dave Kreskowiak13-Mar-13 6:47

Dave Kreskowiak

13-Mar-13 6:47

...and if you've already got the video displaying in your app, why would you need to record it again?? Or is this live video from a camera or other source, such as YouTube??

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Help! Create File

makhondi13-Mar-13 0:59

makhondi

13-Mar-13 0:59

I have a project where I need to be able to make film (.avi) of panel.

For example:

SaveAvi(panel1);

Re: Help! Create File

Garth J Lancaster13-Mar-13 1:12

Garth J Lancaster

13-Mar-13 1:12

well, we're not exactely mind-readers here, and you give us sfa on what you've tried, and what your issues really are ..

so I suggest you start here (see link), and when you have a specific issue, post back a decent question with/about a code issue

A Simple C# Wrapper for the AviFile Library[^]

'g'

Re: Help! Create File

Pete O'Hanlon13-Mar-13 1:13