Re: Solution for: throwing exception classes explicitly
On 8 Maj, 16:41, "nospam_n...@wanano.net"
<Torsten.Reich...@wanano.net> wrote:
Thank you Keith Halligan.
To keep the information in the signatures, we now use an empty
declarative substitute, so the developer can see from the header, what
he might have to catch.
I recommend a much better solution: do not use exception
specifications. Instead have the specification in a comment:
void setErrNo(int i); // throws Exception
Exception specifications really are more of less useless and will
often make the code slower and (more important) difficult to maintain/
extend. The comment is harmless here.
I assume that you do not expect the immediate caller to catch the
exception? In that case, using return codes would seem like a better
idea.
Last, I do not understand that usage of "auto". What is it for? The
keyword is clearly superflous here.
/Peter
#include "iostream"
#if ( GCC_VERSION > 30000 )
# define declare_throw(Exception) throw(Exception)
#else
# define declare_throw(Exception)
#endif
class Exception {
public:
Exception(int);
void setErrNo(int i) declare_throw(Exception);
int errNo;
};
Exception::Exception(int e) {
errNo=e;
}
void Exception::setErrNo(int i) declare_throw(Exception) {
auto Exception methodException(2);
errNo=i;
throw(methodException);
};
int main(char argc, char *argv[], char *env[]) {
try {
auto Exception mainException(1);
mainException.setErrNo(42);
} catch (Exception caughtException) {
std::cout << "caught caughtException:" << caughtException.errNo <<
std::endl;
}
}
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