https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67853
Bug ID: 67853
Summary: decltype of parenthesized xvalue does not correctly
yield rvalue-reference
Product: gcc
Version: 5.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: t...@think-cell.com
Target Milestone: ---
The following code snippet contains the parenthesized decltype of an xvalue:
#include <type_traits>
struct Member {};
struct A { Member x; };
A MakeA();
static_assert(std::is_same<decltype((MakeA().x)), Member&&>::value, ""); //
MSVC++ 2015
//static_assert(std::is_same<decltype((MakeA().x)), Member>::value, ""); //
clang, gcc
The standard says in ยง7.1.6.2 about decltype(e)
(4.1) [...] unparenthesized case, does not apply here
(4.2) if e is an xvalue, decltype(e) is T&&, where T is the type of e;
This means clang and gcc are not standard-conformant.
