Positioning of catch(...)

[Taras_96]

Hi everyone,

I recently came across a quiz question. Does the standard say anything
about catch(...) being the first catch statement?

try
{
}
catch(...) // <- 'hides' subsequent catching
{
}
catch(A)
{
}
catch(B)
{
}

I've seen numerous examples where catch(...) appears first (eg:
Bjorne), but code doesn't compile using MS C++, so does this mean that
the standard allows it, but some compilers don't?

Taras

[Jeff Schwab]

Re: Positioning of catch(...)

Pranav wrote:

From Wheer can I get C++ standard or it is just Bjarne Strostrup CPP
book..,

http://www.parashift.com/c++-faq-lite/big-picture.html#faq-6.13

[Juha Nieminen]

Re: Positioning of catch(...)

Kai-Uwe Bux wrote:

That says that a program where catch(...) is not the last handler in a block
is ill-formed ("shall").

What does "ill-formed" mean in practice? Does it have something to do
with "undefined behavior"?

[=?UTF-8?B?RXJpayBXaWtzdHLDtm0=?=]

Re: Positioning of catch(...)

On 2008-10-13 18:36, Juha Nieminen wrote:

Kai-Uwe Bux wrote:

>That says that a program where catch(...) is not the last handler in a block
>is ill-formed ("shall").

>
What does "ill-formed" mean in practice? Does it have something to do
with "undefined behavior"?

I believe that ill-formed code is not required to compile, while
undefined behaviour refers to the run-time behaviour (which means that
the code did compile).

--
Erik Wikström

[James Kanze]

Re: Positioning of catch(...)

On Oct 13, 6:39 pm, Erik Wikström <Erik-wikst...@telia. comwrote:

On 2008-10-13 18:36, Juha Nieminen wrote:

Kai-Uwe Bux wrote:

That says that a program where catch(...) is not the last
handler in a block is ill-formed ("shall").

What does "ill-formed" mean in practice? Does it have
something to do with "undefined behavior"?

I believe that ill-formed code is not required to compile,
while undefined behaviour refers to the run-time behaviour
(which means that the code did compile).

Sort of. Ill-formed means that the compiler must issue a
diagnostic. Having done so, it is free to compile the code if
it wishes. (Good compilers generally don't.) Undefined
behavior means just that---whatever the compiler does with the
code is correct as far as the standard is concerned. It may
refuse to compile it (with or without an error message); it may
compile it do something that works; or it may compile it to do
anything else.

--
James Kanze (GABI Software) email:james.kan ze@gmail.com
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