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<system_error> header leads to name clashesSection: 19.5 [syserr] Status: Resolved Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2016-01-28
Priority: Not Prioritized
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Discussion:
The most recent state of
N2241
as well as the current draft
N2284
(section 19.5 [syserr], p.2) proposes a
new
enumeration type posix_errno immediatly in the namespace std. One of
the enumerators has the name invalid_argument, or fully qualified:
std::invalid_argument. This name clashes with the exception type
std::invalid_argument, see 19.2 [std.exceptions]/p.3. This clash makes
e.g. the following snippet invalid:
#include <system_error>
#include <stdexcept>
void foo() { throw std::invalid_argument("Don't call us - we call you!"); }
I propose that this enumeration type (and probably the remaining parts
of
<system_error> as well) should be moved into one additional inner
namespace, e.g. sys or system to reduce foreseeable future clashes
due
to the great number of members that std::posix_errno already contains
(Btw.: Why has the already proposed std::sys sub-namespace from
N2066
been rejected?). A further clash candidate seems to be
std::protocol_error
(a reasonable name for an exception related to a std network library,
I guess).
Another possible resolution would rely on the proposed strongly typed enums, as described in N2213. But maybe the forbidden implicit conversion to integral types would make these enumerators less attractive in this special case?
Proposed resolution:
Fixed by issue 7 of N2422.