Empty catch

[DaTurk]

What's the CLI equivalent of the empty catch?

i.e.
try{}
catch
{}

[William DePalo [MVP VC++]]

Re: Empty catch

"DaTurk" <mmagdits@hotma il.comwrote in message
news:1179770123 .946621.121980@ y2g2000prf.goog legroups.com...

What's the CLI equivalent of the empty catch?
>
i.e.
try{}
catch
{}

How about this:

try
{
Console::WriteL ine(L"Hello World");
}

catch ( Exception^ )
{
}

Regards,
Will

[=?Utf-8?B?RGF2aWQgQW50b24=?=]

RE: Empty catch

try
{
}
catch(...)
{
}

--
David Anton

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"DaTurk" wrote:

What's the CLI equivalent of the empty catch?
>
i.e.
try{}
catch
{}
>
>

[SvenC]

Re: Empty catch

DaTurk wrote:

What's the CLI equivalent of the empty catch?
>
i.e.
try{}
catch
{}

Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?

--
SvenC

[Carl Daniel [VC++ MVP]]

Re: Empty catch

"SvenC" <SvenC@communit y.nospamwrote in message
news:e4DEQODnHH A.3736@TK2MSFTN GP03.phx.gbl...

DaTurk wrote:

>What's the CLI equivalent of the empty catch?
>>
>i.e.
>try{}
>catch
>{}

>
Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?

It's allowed in C#. It's equivalent to the C++/CLI construct:

try
{
}
catch(Exception ^)
{
}

Using catch(...) will also catch native exceptions, and possibly structured
(platform) exceptions, depending on the compiler options used.

-cd

[DaTurk]

Re: Empty catch

On May 22, 12:39 am, "SvenC" <S...@community .nospamwrote:

DaTurk wrote:

What's the CLI equivalent of the empty catch?

>

i.e.
try{}
catch
{}

>
Where is that empty catch allowed? It is not standard C++. Do you mean
catch(...) ?
>
--
SvenC

My apologies, I was refering to c#

[Jochen Kalmbach [MVP]]

Re: Empty catch

Hi Carl!

>>>What's the CLI equivalent of the empty catch?
>>>
>>>i.e.
>>>try{}
>>>catch
>>>{}

>
It's allowed in C#. It's equivalent to the C++/CLI construct:
>
try
{
}
catch(Exception ^)
{
}

No. "catch(Exceptio n^)" is *not* the same as "catch" in C#!

"catch(Exceptio n^)" will *only* catch exceptions which are derived from
"System.Excepti on"!

"catch" will catch *all* Exceptions (derived from "System.Object" )!
It also will catch native exceptins in C#!!!


Therefor the C++/CLI equivalent of "catch" is "catch(System:: Object^)" !



See also: Basic Concepts in Using Managed Exceptions
http://msdn2.microsoft.com/en-us/lib...b6(VS.80).aspx


--
Greetings
Jochen

My blog about Win32 and .NET

http://blog.kalmbachnet.de/

[Jochen Kalmbach [MVP]]

Re: Empty catch

DaTurk schrieb:

What's the CLI equivalent of the empty catch?
>
i.e.
try{}
catch
{}

try {}
catch(System::O bject^)
{}

--
Greetings
Jochen

My blog about Win32 and .NET

http://blog.kalmbachnet.de/

[Carl Daniel [VC++ MVP]]

Re: Empty catch

"Jochen Kalmbach [MVP]" <nospam-Jochen.Kalmbach @holzma.dewrote in message
news:%23L8hGRLn HHA.4848@TK2MSF TNGP05.phx.gbl. ..

Hi Carl!
>

>>>>What's the CLI equivalent of the empty catch?
>>>>
>>>>i.e.
>>>>try{}
>>>>catch
>>>>{}

>>
>It's allowed in C#. It's equivalent to the C++/CLI construct:
>>
>try
>{
>}
>catch(Exceptio n^)
>{
>}

>
No. "catch(Exceptio n^)" is *not* the same as "catch" in C#!
>
"catch(Exceptio n^)" will *only* catch exceptions which are derived from
"System.Excepti on"!
>
"catch" will catch *all* Exceptions (derived from "System.Object" )!
It also will catch native exceptins in C#!!!

Egads!

I'd forgotten that the CLR actually supporting throwing something not
derived from System.Exceptio n!

-cd

[Ben Voigt]

Re: Empty catch

It also will catch native exceptins in C#!!!

Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
that only for p/invoke?

[Jochen Kalmbach [MVP]]

Re: Empty catch

Hi Ben!

>It also will catch native exceptins in C#!!!

>
Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
that only for p/invoke?

SEHException is also derived from "System.Excepti on". But you can throw
*any* object as an exception. Therefor, if you want to catch *all*
exceptions, you need to catch "System.Obj ect" instead of "System.Excepti on"!

See:

#pragma unmanaged

void Test1()
{
throw 1;
}

#pragma managed

void Test2()
{
throw 2;
}

void Test3()
{
throw gcnew System::Object( );
}

int main()
{
try
{
Test1();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st1: " + o->GetType()->ToString());
}

try
{
Test2();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st2: " + o->GetType()->ToString());
}

try
{
Test3();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st3: " + o->GetType()->ToString());
}
}


Output is:
Test1: System.Runtime. InteropServices .SEHException
Test2: System.Runtime. InteropServices .SEHException
Test3: System.Object

Greetings
Jochen

[Ben Voigt]

Re: Empty catch


"Jochen Kalmbach [MVP]" <nospam-Jochen.Kalmbach @holzma.dewrote in message
news:enBVzKQnHH A.4628@TK2MSFTN GP06.phx.gbl...

Hi Ben!

>>It also will catch native exceptins in C#!!!

>>
>Wouldn't catch (Exception^) do so as well, giving an SEHException? Or is
>that only for p/invoke?

>
SEHException is also derived from "System.Excepti on". But you can throw
*any* object as an exception. Therefor, if you want to catch *all*
exceptions, you need to catch "System.Obj ect" instead of
"System.Excepti on"!
>
See:

I wasn't doubting that catching System.Object will catch all exceptions...
but wouldn't catching System.Exceptio n also catch all exceptions, decoding
managed objects derived from Exception, and wrapping everything else in
SEHException?

>
#pragma unmanaged
>
void Test1()
{
throw 1;
}
>
#pragma managed
>
void Test2()
{
throw 2;
}
>
void Test3()
{
throw gcnew System::Object( );
}
>
int main()
{
try
{
Test1();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st1: " + o->GetType()->ToString());
}
>
try
{
Test2();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st2: " + o->GetType()->ToString());
}
>
try
{
Test3();
}
catch(System::O bject ^o)
{
System::Console ::WriteLine("Te st3: " + o->GetType()->ToString());
}
}
>
>
Output is:
Test1: System.Runtime. InteropServices .SEHException
Test2: System.Runtime. InteropServices .SEHException
Test3: System.Object
>
Greetings
Jochen

[Jochen Kalmbach [MVP]]

Re: Empty catch

Hi Ben!

I wasn't doubting that catching System.Object will catch all exceptions...
but wouldn't catching System.Exceptio n also catch all exceptions, decoding
managed objects derived from Exception, and wrapping everything else in
SEHException?

I don't understand the background of this question?

I don't know the internals of every assembly; so I don't know if
"System.Excepti on" will catch *all* exceptions... regardless of
SEHException...

Greetings
Jochen

[Mattias Sjögren]

Re: Empty catch

>I wasn't doubting that catching System.Object will catch all exceptions...

>but wouldn't catching System.Exceptio n also catch all exceptions, decoding
>managed objects derived from Exception, and wrapping everything else in
>SEHException ?

>
>I don't understand the background of this question?
>
>I don't know the internals of every assembly; so I don't know if
>"System.Except ion" will catch *all* exceptions... regardless of
>SEHException.. .

You can also use the RuntimeCompatib ilityAttribute on your assembly
with WrapNonExceptio nThrows = true to make sure all exceptions you see
are derived from Exception (if they aren't already, they get wrapped
in a RuntimeWrappedE xception). That's what C# does for example.


Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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