Here's an annoying regression:
-----------------------------
struct S {
typedef double value_type;
};
template <typename T> struct Traits {
typedef const typename T::value_type dereference_type;
};
template <class BlockVectorType> struct ConstIterator {
typedef typename Traits<BlockVectorType>::dereference_type
dereference_type;
dereference_type operator * () const { return 0; }
};
template class ConstIterator<S>;
---------------------
For this, we get:
deal.II/lac> g++ -W -Wall -c a.cc
a.cc: In instantiation of 'ConstIterator<S>':
a.cc:16: instantiated from here
a.cc:13: warning: type qualifiers ignored on function return type
We didn't use to produce this warning. I also think it's hard to avoid:
if the class S would declare its value_type as a reference, then the
addition of the 'const' in the Traits class would matter; here, it doesn't,
but that's only because of chance.
What's worse is that the warning is also inconsistent: if we replace
template <class BlockVectorType> struct ConstIterator {
typedef typename Traits<BlockVectorType>::dereference_type
dereference_type;
by
template <class BlockVectorType> struct ConstIterator {
typedef const typename BlockVectorType::value_type dereference_type;
then the warning goes away despite the fact that the actual types are
exactly the same. Weird.
W.
--
Summary: [4.3/4.4 regression] bogus "type qualifiers ignored"
warning
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: diagnostic
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=36052
