Created on 2014-07-08.00:00:00 last changed 95 months ago
Proposed resolution:
This wording is relative to N4081 in regard to fundamental-ts changes.
Edit §3.2.2 [tuple.apply] paragraph 2:
template <class F, class Tuple> constexpr decltype(auto) apply(F&& f, Tuple&& t);-2- Effects: Given the exposition only function
template <class F, class Tuple, size_t... I> constexpr decltype(auto) apply_impl( // exposition only F&& f, Tuple&& t, index_sequence<I...>) { return INVOKE(std::forward<F>(f)(, std::get<I>(std::forward<Tuple>(t))...); }[…]
[ 2015-02, Cologne ]
DK: We should use the new std::invoke.
TK: Is this a defect?
AM: std::invoke goes into C++17, and this is a defect against a TS based on C++14. We can change this later,
but now leave it as INVOKE.
GR: The TS lets you have Editor's Notes, so leave a note to make that change for C++17.
[…]
GR: I can't see how we can assume this is part of the design. I cannot believe it was ever intended for this
design to exclude function pointers.
AM: I can give you the exact evolution: We had "apply" as an example explaining the usefulness of index_sequence.
Then someone looked at it and said, "why isn't this in the Standard". NJ to VV: Why are you against useful steps?
We are trying to converge on a consistent standard across multiple documents. The alternative is to reopen this
in a later discussion.
VV: All I said is that this is not defect, whether or not people like it.
AM: So you'd be fine with the issue, but not as a DR?
Straw poll: Who's happy to make this tentatively ready as a DR against the Fundamentals TS?
Lots of agreement, no opposition, 3 neutrals
Addresses: fund.ts
The definition of apply present in §3.2.2 [tuple.apply] prevents this function template to be used with pointer to members type passed as the first argument.
Effects:[…]
return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
This makes this utility inconsistent with other standard library components and limits its usability.
We propose to define its functionally in terms of INVOKE.
History | |||
---|---|---|---|
Date | User | Action | Args |
2017-07-30 20:10:41 | admin | set | status: wp -> open |
2015-05-22 18:31:21 | admin | set | status: ready -> wp |
2015-03-22 19:14:56 | admin | set | messages: + msg7248 |
2015-03-22 19:14:56 | admin | set | status: new -> ready |
2014-10-05 14:13:26 | admin | set | messages: + msg7097 |
2014-07-08 00:00:00 | admin | create |