Starting with version 4.0 G++ fails to accept this testcase:
bool f(int i) { return i != 5; }
template <class X, class P = bool(X)>
struct Traits
{
typedef P type;
};
template <class X, class P = typename Traits<X>::type>
struct S
{
const P& p_;
S( const P& p ) : p_(p) {} // const reference
};
template <class X>
S<X> make_s(const typename Traits<X>::type & p) // const reference
{
return S<X>(p); // << HERE
}
int main()
{
make_s<int>(f);
}
because the parameter of make_s<int> ends up with reference to const function
type. This is wrong; applying const to a function type should produce the same
function type, not a const variant.
--
Summary: [4.3/4.4/4.5/4.6 Regression] function types, cv-quals
and typename
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
AssignedTo: jason at gcc dot gnu dot org
ReportedBy: jason at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44193
