deriving from std::exception

[Noah Roberts]

I am having some problems with deriving the std::exception class. My
compiler (g++-2.95) works with it just fine, but it does in a lot of
broken cases. I have a user/developer that can't compile the following
code:

class CFENException : public std::exception
{
std::string _what;

public:
CFENException(s td::string what) : _what(what) {}
virtual const char* what() const throw() { return _what.c_str(); }
};

He is getting the following error from dev-c++ 4.9.8.1:
line 57 in BitBoard.h: looser throw specifier for 'virtual
line 54 in exception: overriding 'virtual

Isn't throw() the tightest specifier you can get? It says this method
cannot throw anything right?

My book on the c++ std, The C++ Standard Library by Josuttis, says the
above is the correct way to derive the exception class. So WTF am I
doing wrong if anything?

Thanks for any help,
NR

[Alexander Terekhov]

Re: deriving from std::exception


Noah Roberts wrote:[color=blue]
>
> I am having some problems with deriving the std::exception class. My
> compiler (g++-2.95) works with it just fine, but it does in a lot of
> broken cases. I have a user/developer that can't compile the following
> code:
>
> class CFENException : public std::exception
> {
> std::string _what;
>
> public:
> CFENException(s td::string what) : _what(what) {}[/color]

Add ~CFENException( ) throw() {}
[color=blue]
> virtual const char* what() const throw() { return _what.c_str(); }[/color]

what() is brain-damaged.
[color=blue]
> };[/color]

Almost the entire C++ EH just sucks miserably, BTW.

regards,
alexander.

[Alexander Terekhov]

Re: deriving from std::exception


"Alf P. Steinbach" wrote:
[...][color=blue]
> And possibly also mail a bug-report ...[/color]

http://google.com/groups?threadm=3EC0ECAA.6520B266%40web.de

(Subject: Exception handling... it's time to fix the standard)

"I believe that ALL dtors shall have an implicit throw()-
nothing exception-spec imposed on them. "

regards,
alexander.

[Greg P.]

Re: deriving from std::exception

"Alf P. Steinbach" <alfps@start.no > wrote in message
news:3f299c2e.4 08314828@News.C IS.DFN.DE...
| I very much doubt it. If it really does, please post some quote
| here. And possibly also mail a bug-report to the author.
What page(s) is this on?