Will VC++ 2005 implement switch with case int::typeid in the final release?

  • Thread starter Thread starter nobody
  • Start date Start date
N

nobody

With Visual C++ 2005 beta 2, I get the below compling error for the
following code. I think this error is not acceptable to me because
int::typeid is a constant and is known to compiler when compiling. Will VC++
2005 implement switch with case int::typeid in the final release?

error C2450: switch expression of type 'System::Type ^' is illegal

1> No user-defined-conversion operator available, or

1> Integral expression required

1>.\sproadapter.cpp(271) : error C2051: case expression not constant



Type ^t = obData->GetType();

switch (t)

{

case int::typeid:

break;

default:

break;

}
 
I believe that C++ doesn't care about constantness, it just takes only int
(or type with implicit cast to int) argument.
 
nobody said:
With Visual C++ 2005 beta 2, I get the below compling error for the
following code. I think this error is not acceptable to me because
int::typeid is a constant and is known to compiler when compiling.
Will VC++ 2005 implement switch with case int::typeid in the final
release?
Click to expand...

No.

System::Type is not an integer type and therefore cannot be used as the type
of a switch/case regardless of real or apparent const-ness.

-cd
 
Consider the following code:

Type ^t = obData->GetType();

if(t == int::typeid)

{

//do something

}

else if(t == __int64::typeid)

{

Type ^t = obData->GetType();

}

else if(t == double::typeid)

{

Type ^t = obData->GetType();

}

else if(t == float::typeid)

{

Type ^t = obData->GetType();

}

else

{

}



If I can use switch, it will much better. Do you know any method to use
switch?
 
Consider the following code:
If I can use switch, it will much better. Do you know any method to use
switch?
Click to expand...

No, you can't. Depending on what you're doing you might be able to implement
a table driven approach, but that's about it.
 
nobody said:
If I can use switch, it will much better. Do you know any method to use
switch?
Click to expand...

While everyone else is correct that this is not supported by the C++
language, you can request that it be supported (see link to feedback below).
This request is very similar to another feature which we do not support --
switch on strings. C# supports switch on strings. The code generated in both
your case and the string case would effectively be a series of if-then-else
statements.
 
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