1) The synopsis of std::system_error in [syserr.syserr.overview]
should add the following line as the last part of the class
definition:

private:
  mutable string msg; // For exposition only

Otherwise the implementation hint provided in p. 6 seems
incomplete.

2) In [syserr.syserr.overview] we have the class definition of
std::system_error. In contrast to all exception classes, which
are constructible with a what_arg string (see [std.exceptions],
or ios_base::failure in [ios::failure]), only overloads with with
const string& are possible. For consistency with the re-designed
remaining exception classes this class should also provide
c'tors which accept a const char* what_arg string.

Please note that this proposed addition makes sense even
considering the given implementation hint for what(), because
what_arg is required to be set as what_arg of the base class
runtime_error, which now has the additional c'tor overload
accepting a const char*.

Greetings from Bremen,

Daniel Kr   gler


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Daniel Kr=FCgler wrote:
> 1) The synopsis of std::system_error in [syserr.syserr.overview]
> should add the following line as the last part of the class
> definition:
>=20
> private:
>   mutable string msg; // For exposition only
>=20
> Otherwise the implementation hint provided in p. 6 seems
> incomplete.
>=20

I'll think about it, but my initial inclination is to leave it as it is.=20
First, it's a hint, not a requirement. Second, it's in a note, so it's=20
not a requirement. <g> Yes, the hint is incomplete. I don't see any harm=20
in that.

--=20

 -- Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com)
Author of "The Standard C++ Library Extensions: a Tutorial and=20
Reference." (www.petebecker.com/tr1book)

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