https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68012
Bug ID: 68012
Summary: g++ incorrectly accepts forward declaration of
constexpt variable template
Product: gcc
Version: 5.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: morwenn29 at hotmail dot fr
Target Milestone: ---
I had the following piece of code in one of my projects:
template<typename>
constexpr std::size_t iterator_category_value;
g++5.2 is happy with it but clang is not and complains, saying that it
shouldn't be possible to forward-declare a constexpr whatever. To be sure, I
asked the question on StackOverflow:
http://stackoverflow.com/q/33197817/1364752
It seems that this code should not be accepted, and a defect report seems to
agree that it should be rejected: http://wg21.cmeerw.net/cwg/issue1712
