https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71534
Bug ID: 71534
Summary: Initializing a static constexpr data member of a base
class by using a static constexpr data member of a
derived class should be an error
Product: gcc
Version: 6.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: michele.caini at gmail dot com
Target Milestone: ---
Consider the following code:
template<typename T>
struct S { static constexpr int bar = T::foo; };
struct U: S<U> { static constexpr int foo = 42; };
int main() { }
GCC compiles it, but it shouldn't.
The type T is not a complete type when bar is initialized.
Here is a discussion on stackoverflow where reasons are discussed:
http://stackoverflow.com/questions/37816186/initializing-a-static-constexpr-data-member-of-the-base-class-by-using-a-static
Link to the standard (working draft) are provided as well in the discussion.
Other compilers (mostly clang) correctly reject it.
