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From: "hewillk at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/100824] New: ranges::size should treat the subexpression as an lvalue Date: Sat, 29 May 2021 11:17:03 +0000 [thread overview] Message-ID: <bug-100824-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100824 Bug ID: 100824 Summary: ranges::size should treat the subexpression as an lvalue Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: hewillk at gmail dot com Target Milestone: --- The CPO described in [range.access] treats the subexpression E as an lvalue, but ranges::size, ranges::empty, and ranges::data forward E perfectly, which makes the following case behavior wrong: https://godbolt.org/z/7KoT3WE41 #include <ranges> #include <array> struct R : std::ranges::view_base { constexpr int* begin() & { return nullptr; } constexpr int* end() & { return nullptr; } constexpr int size() & { return 42; } }; template <> inline constexpr bool std::ranges::enable_borrowed_range<R> = true; // call ranges::end(e) - ranges::begin(e) incorrectly static_assert(std::ranges::size(R{})); int main() { std::array r{42, 42, 42}; // call e.data() correctly (r | std::views::all).data(); // call std::to_address(ranges::begin(e)) incorrectly std::ranges::data(r | std::views::all); }
next reply other threads:[~2021-05-29 11:17 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-29 11:17 hewillk at gmail dot com [this message] 2021-06-03 15:13 ` [Bug libstdc++/100824] " redi at gcc dot gnu.org 2021-06-04 11:39 ` redi at gcc dot gnu.org 2021-06-04 14:59 ` cvs-commit at gcc dot gnu.org 2021-06-04 16:52 ` hewillk at gmail dot com 2021-06-04 19:18 ` redi at gcc dot gnu.org 2021-06-04 20:42 ` cvs-commit at gcc dot gnu.org 2021-06-04 20:48 ` redi at gcc dot gnu.org 2021-06-05 3:16 ` hewillk at gmail dot com 2021-06-05 6:35 ` redi at gcc dot gnu.org 2021-06-05 10:45 ` cvs-commit at gcc dot gnu.org 2021-06-11 22:25 ` cvs-commit at gcc dot gnu.org 2021-06-11 22:25 ` cvs-commit at gcc dot gnu.org 2021-06-11 22:25 ` cvs-commit at gcc dot gnu.org 2022-09-07 12:32 ` redi at gcc dot gnu.org 2022-09-07 12:32 ` redi at gcc dot gnu.org
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