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2493. initializer_list supports incomplete classes

Section: 21.9 [support.initlist] Status: New Submitter: David Krauss Opened: 2015-04-27 Last modified: 2017-02-03

Priority: 4

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The typical use-case of std::initializer_list<T> is for a pass-by-value parameter of T's constructor. However, this contravenes [res.on.functions]/2.5 because initializer_list doesn't specifically allow incomplete types (as do for example std::unique_ptr (23.11.1 [unique.ptr]/5) and std::enable_shared_from_this (23.11.6 [util.smartptr.enab]/2)).

A resolution would be to copy-paste the relevant text from such a paragraph.

Proposed resolution: