template<typename T>
struct is_int
{
static const bool value = false;
};
template <>
struct is_int<int>
{
static const bool value = true;
};
template <bool Cond, typename T = void>
struct enable_if
{};
template <typename T>
struct enable_if<true, T>
{ typedef T type; };
class test
{
public:
template <typename T>
typename enable_if<is_int<T>::value>::type func(T x)
{}
template <typename T>
typename enable_if<!is_int<T>::value>::type func(T x)
{}
};
fails to compile on 4.0.2 with
t2.cpp:29: error: template<class T> typename enable_if<(! is_int<T>::value),
void>::type test::func(T) cannot be overloaded
t2.cpp:25: error: with template<class T> typename enable_if<is_int<T>::value,
void>::type test::func(T)
fails to compile on 3.4.2 with
t2.cpp:30: error: `template<class T> typename enable_if<(! is_int<T>::value),
void>::type test::func(T)' and `template<class T> typename enable_if<
is_int<T>::value, void>::type test::func(T)' cannot be overloaded
However the same two functions will compile when not defined as part of a class
<insert the enable_if and is_int from above>
template <typename T>
typename enable_if<is_int<T>::value>::type func(T x)
{}
template <typename T>
typename enable_if<!is_int<T>::value>::type func(T x)
{}
both msvc7.1 and Comeau 4.3.3 will accept it.
I don't think that this is duplicate of 15882.
The problem appears to be that syntax checking is catching this before SFINAE
has a chance to prune the overload set. At any rate there are not template
instantiations in the test case.
--
Summary: Overload errors generated without template
instantiations for class member templates
Product: gcc
Version: 4.0.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: nem3 at pitt dot edu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24915
