This may be related to PR25868, but looks simpler. Take this
piece of code that certainly looks valid to me:
----------------------
template <int dim> class X {};
template <class T> class Y {
static const unsigned int dim = 1;
X<dim> f();
};
template <class T>
X<Y<T>::dim> Y<T>::f() { return X<dim>(); }
---------------------
We reject the code with 3.3, 3.4, 4.0, 4.1, and mainline. I don't have any
older compilers here to check prior versions. The message is this:
-----------------
g/y> ~/tmp/build/gcc/mainline/bin/c++ -c x.cc
x.cc:12: error: prototype for 'X<Y<T>::dim> Y<T>::f()' does not match any in
class 'Y<T>'
x.cc:8: error: candidate is: X<1> Y<T>::f()
x.cc:12: error: template definition of non-template 'X<Y<T>::dim> Y<T>::f()'
-----------------
Since Y<T>::dim == 1, the function really does match its prototype,
despite the error. So this is a rejects-valid.
W.
--
Summary: Rejects template with local static variable used in
return type
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: bangerth at dealii dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26261
