DaniWeb Forum Index > Software Development > C#

C# RSS

Generic type-union conflict,error?

Please support our C# advertiser: $4.95 a Month - ASP.NET Web Hosting – Click Here!

Thread Solved

•

Join Date: Oct 2008

Posts: 1,838

Reputation: ddanbe has much to be proud of

Solved Threads: 266

ddanbe

Offline

Posting Virtuoso

Generic type-union conflict,error?

Nov 21st, 2008

Busy writing an infix to postfix converter.(I'm a strange guy. I like to do those things from time to time...)
I have a class Expression which is in essence :

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
 [StructLayout(LayoutKind.Explicit)] //in c/c++ this is a union
        public struct Valoper
        {
            [FieldOffset(0)]
            public int Value;
            [FieldOffset(0)]
            public Oper Operand;
        }
        public Queue<Valoper> RPN = new Queue<Valoper>();
 
        public Queue<Valoper> InfixToPostfix(string expr)
        {
            //change expr to postfix
            return RPN;
        }
 [StructLayout(LayoutKind.Explicit)] //in c/c++ this is a union
        public struct Valoper
        {
            [FieldOffset(0)]
            public int Value;
            [FieldOffset(0)]
            public Oper Operand;
        }
        public Queue<Valoper> RPN = new Queue<Valoper>();

        public Queue<Valoper> InfixToPostfix(string expr)
        {
            //change expr to postfix
            return RPN;
        }

Btw wonder why they left out the union keyword in C#.
I found this "way" to do it in C# on MSDN.
In my Main I have :

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
Expression E = new Expression();
            Queue<Expression.Valoper> Output = E.InfixToPostfix(InputStr);
Expression E = new Expression();
            Queue<Expression.Valoper> Output = E.InfixToPostfix(InputStr);

The last line gives me the error message

Error 1 Cannot implicitly convert type 'System.Collections.Generic.Queue<ConsoleInfixToPostfix.Expression.Valoper>' to 'System.Collections.Generic.Queue<Valoper>

I'm using VS 2008 Express C# here.
What am I doing wrong? Any help would be nice.

Today is a gift, that's why it is called "The Present".
Make love, no war. Cave ab homine unius libri.
Danny

•

Join Date: Aug 2008

Posts: 1,158

Reputation: dickersonka will become famous soon enough

Solved Threads: 136

dickersonka dickersonka is offline

Offline

Veteran Poster

Re: Generic type-union conflict,error?

Nov 21st, 2008

hmmm, compiles fine for me

you sure Expression.Valoper is the same class as Valoper?

Custom Application & Software Development
www.houseshark.net

•

Join Date: Oct 2008

Posts: 1,838

Reputation: ddanbe has much to be proud of

Solved Threads: 266

ddanbe

Offline

Posting Virtuoso

Re: Generic type-union conflict,error?

Nov 21st, 2008

The struct Valoper is defined in the Expression class.
The line with the error I have is called from Main in the Program class. I don't know why it shouldn't work, that's why I posted it here.
Did you really tried it out and it worked at your place?

Today is a gift, that's why it is called "The Present".
Make love, no war. Cave ab homine unius libri.
Danny