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819. rethrow_if_nested

Section: 17.9.8[except.nested]Status:C++11Submitter: Alisdair MeredithOpened: 2008-03-25Last modified: 2016-01-28

Priority:Not Prioritized

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Discussion:

Looking at the wording I submitted forrethrow_if_nested, I don't think Igot it quite right.

The current wording says:

template <class E> void rethrow_if_nested(const E& e);

Effects: Callse.rethrow_nested() only ifeis publicly derived fromnested_exception.

This is trying to be a bit subtle, by requiringe (notE) to be publiclyderived fromnested_exception the idea is that adynamic_cast would berequired to be sure. Unfortunately, ife is dynamically but not staticallyderived fromnested_exception,e.rethrow_nested() is ill-formed.

[San Francisco:]

Alisdair was volunteered to provide wording.

[2009-10 Santa Cruz:]

Leave as Open. Alisdair to provide wording.

[2009-11-09 Alisdair provided wording.]

[2010-03-10 Dietmar updated wording.]

[2010 Pittsburgh:]

Moved to Ready for Pittsburgh.

Proposed resolution:

Change 17.9.8[except.nested], p8:

template <class E> void rethrow_if_nested(const E& e);

-8-Effects:Callse.rethrow_nested()oOnly ifthe dynamic type ofe ispubliclyand unambiguously derived fromnested_exceptionthis callsdynamic_cast<const nested_exception&>(e).rethrow_nested().