https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58848
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
CC| |msebor at gcc dot gnu.org
Resolution|--- |INVALID
--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
The first test case can be reduced to the one below which GCC also accepts.
But based on my reading of the standard, I think the test case is valid because
the definition (including the initialization) of A<0>::v is never instantiated.
(See the quotes from the C++ standard below for reference.)
The second test case requires a diagnostic because the constexpr function
called in a constexpr context with an argument that would cause the throw
expression to be evaluated.
I'm resolving this as Invalid (see also bug 70820 for a similar example.)
Quoting from temp.inst:
-1- The implicit instantiation of a class template specialization causes the
implicit instantiation of the declarations, but not of the definitions, ... of
... static data members.
-11- An implementation shall not implicitly instantiate ... a static data
member of a class template that does not require instantiation.
$ cat xx.cpp && gcc -S -Wall -Wextra -Wpedantic -std=c++11 xx.cpp
template <int>
struct A
{
static constexpr int
f (int i)
{
return i ? i : throw 0;
}
static const int v = f (0);
};
int i = A<0>::f (0);
$
