Re: std::exception what() method
On Mar 28, 7:31 pm, "petek1976" <pete.karou...@earthlink.net> wrote:
Hi,
I have the following exception class:
#include <string>
#include <exception>
class tcClockSynchException : public std::exception
{
public:
explicit tcClockSynchException(const char *apnMsg) : mcMsg(apnMsg) {}
virtual const char *what() const throw() { return mcMsg.c_str(); }
virtual ~tcClockSynchException() throw() {}
private:
std::string mcMsg;
};
I'm a little worried about the what() method. It isn't clear to me
whether or not I can rely on c_str() to not throw any exceptions,
since the what() method in the base class says it will not throw any
exceptions.
Basically, you can not. But this happens to work most of the time.
Does the standard guarantee that c_str() will not throw
any exceptions?
No.
If it doesn't guarantee this what is a better way to
implement my exception class?
Probably you can leave it as is--in my opinion it is good enough.
However, I've used to use std::runtime_error as the base class for
exceptions, like this:
#include <stdexcept>
class tcClockSynchException : public std::runtime_error
{
public:
explicit tcClockSynchException(std::string const& msg) :
std::runtime_error(msg) {}
};
Of course, this is for exceptions which really indicate *runtime*
errors as opposed to logic errors (still, there is a separate class
hierarchy originating from the class std::logic_error).
--
Alex Shulgin
--
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