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From: "zeratul976 at hotmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/54060] New: [C++11] Lambda expression's type should not be in an anonymous namespace Date: Sat, 21 Jul 2012 06:55:00 -0000 [thread overview] Message-ID: <bug-54060-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54060 Bug #: 54060 Summary: [C++11] Lambda expression's type should not be in an anonymous namespace Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: zeratul976@hotmail.com The following code, when in a header file: auto L = [](){}; struct S { decltype(L) m; }; Produces the following warning: test.hpp:3:8: warning: 'S' has a field 'S::m' whose type uses the anonymous namespace [enabled by default] struct S ^ This warning suggests that the type of the lambda is in an anonymous namespace. A similar warning is given if L is declared at namespace or class scope: namespace N { auto L = [](){}; } struct S { decltype(N::L) m; }; class N { static constexpr auto L = [](){}; }; struct S { decltype(N::L) m; }; According to section 5.1.2/3 of the Standard, "The type of the lambda-expression (which is also the type of the closure object) is a unique, unnamed nonunion class type — called the closure type — whose properties are described below. This class type is not an aggregate (8.5.1). The closure type is declared in the smallest block scope, class scope, or namespace scope that contains the corresponding lambda-expression." This suggests that the types of the lambdas in the above examples should not be in an anonymous namespace, because that would not be the smallest scope that contains the lambda-expression.
next reply other threads:[~2012-07-21 6:55 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-07-21 6:55 zeratul976 at hotmail dot com [this message] 2012-07-31 19:15 ` [Bug c++/54060] G++ warning mixes up anonymous types and anonymous namespaces jason at gcc dot gnu.org 2012-07-31 20:22 ` zeratul976 at hotmail dot com 2012-07-31 20:42 ` redi at gcc dot gnu.org 2013-06-15 18:16 ` paolo.carlini at oracle dot com
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