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From: "mail at 3v1n0 dot net" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/94554] spurious -Waddress warning within "if constexpr" function-null compares Date: Thu, 01 Oct 2020 17:54:09 +0000 [thread overview] Message-ID: <bug-94554-4-AL36xBFhTt@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-94554-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94554 Marco Trevisan <mail at 3v1n0 dot net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mail at 3v1n0 dot net --- Comment #5 from Marco Trevisan <mail at 3v1n0 dot net> --- I don't think g++ is totally wrong here, Actually, if any, it should be stronger in making the error clearer and louder, as per sé it's fine to consider that you're for real not comparing something constant and the function address may not be known at compile time, so not wrong to check. However, something that will not error but work can be something like: #include <iostream> #include <type_traits> using namespace std; int meow() { return 1; } void kitty(int i) { std::cout << "Mowed vlaue " << i << "\n"; } template <int (*F)()> void test() { using NullType = std::integral_constant<decltype(F), nullptr>; using ActualType = std::integral_constant<decltype(F), F>; if constexpr (!std::is_same_v<ActualType, NullType>) { kitty(F()); } else { kitty(222222); } } int main() { test<nullptr>(); test<meow>(); return 0; }
next prev parent reply other threads:[~2020-10-01 17:54 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-10 18:58 [Bug c++/94554] New: " myriachan at gmail dot com 2020-04-10 20:20 ` [Bug c++/94554] " mpolacek at gcc dot gnu.org 2020-04-10 20:22 ` myriachan at gmail dot com 2020-04-14 21:56 ` daniel.kruegler at googlemail dot com 2020-07-10 15:13 ` lts-rudolph at gmx dot de 2020-10-01 17:54 ` mail at 3v1n0 dot net [this message] 2022-06-23 4:25 ` jason at gcc dot gnu.org 2022-06-23 4:31 ` jason at gcc dot gnu.org 2022-06-23 15:08 ` cvs-commit at gcc dot gnu.org 2022-06-23 15:44 ` jason at gcc dot gnu.org
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