https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86581
Bug ID: 86581
Summary: constexpr variable is not checked
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: zhonghao at pku dot org.cn
Target Milestone: ---
The code is as follow:
template<typename> struct V {
union { int n; struct { int x,y; }; };
constexpr V() : x(0) {}
};
constexpr V<int> v;
g++ does not check whether v is initialized. Instead, clang++ does that:
code0.cpp:6:18: error: constexpr variable 'v' must be initialized by a
constant expression
constexpr V<int> v;
^
code0.cpp:6:18: note: subobject of type 'int' is not initialized
1 error generated.
