[Bug c++/86581] constexpr variable is not checked

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86581

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-07-19
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced:

struct V {
 union { int n; struct { int x,y; }; };

 constexpr V() : x(0) {} 
}; 
constexpr V v;



Clang says:

un.cc:4:12: error: constexpr constructor must initialize all members
 constexpr V() : x(0) {} 
           ^
un.cc:2:37: note: member not initialized by constructor
 union { int n; struct { int x; int y; }; };
                                    ^
un.cc:6:13: error: no matching constructor for initialization of 'const V'
constexpr V v;
            ^
un.cc:1:8: note: candidate constructor (the implicit copy constructor) not
viable: requires 1 argument, but 0 were provided
struct V {
       ^
un.cc:1:8: note: candidate constructor (the implicit move constructor) not
viable: requires 1 argument, but 0 were provided
2 errors generated.