This page is a snapshot from the LWG issues list, see the Library Active Issues List for more information and the meaning of Open status.

2136. Postconditions vs. exceptions

Section: 15.4.1 [structure] Status: Open Submitter: Jens Maurer Opened: 2012-03-08 Last modified: 2016-02-10

Priority: 3

View all issues with Open status.


The front matter in clause 17 should clarify that postconditions will not hold if a standard library function exits via an exception. Postconditions or guarantees that apply when an exception is thrown (beyond the basic guarantee) are described in an "Exception safety" section.

[ 2012-10 Portland: Move to Open ]

Consensus that we do not clearly say this, and that we probably should. A likely location to describe the guarantees of postconditions could well be a new sub-clause following [res.on.required] which serves the same purpose for requires clauses. However, we need such wording before we can make progress.

Also, see 2137 for a suggestion that we want to see a paper resolving both issues together.

[2015-05-06 Lenexa: EirkWF to write paper addressing 2136 and 2137]

MC: Idea is to replace all such "If no exception" postconditions with "Exception safety" sections.

Proposed resolution: