this is related to these two questions:
the second one is mine
the issue is when i moved to TDM-GCC 64 the following code (previously working) does not compile I made sure c++11 is enabled.
I took the remove_all_pointers from the first question, and combined it with the answer to my question(bullet #2).
The following is my (previously) compilable example
#include <iostream>
#include <type_traits>
using namespace std;
template <typename T> class remove_all_pointers{
public:
typedef T type;
};
template <typename T> class remove_all_pointers<T*>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* const>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* volatile>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* const volatile >{
public:
typedef typename remove_all_pointers<T>::type type;
};
class OverVoid{
public:
static bool isOverVoid (){
return true;
}
virtual ~OverVoid(){
}
};
class Meta: public OverVoid{
};
class Physical{
public:
};
template<typename _Ty,typename = typename std::enable_if<std::is_base_of<OverVoid, remove_all_pointers<_Ty>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<_Ty>::type::isOverVoid()<<endl;
}
};
template<typename _Ty,typename = typename std::enable_if<std::is_base_of<OverVoid, remove_all_pointers<_Ty>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<_Ty>::type::isOverVoid()<<endl;
}
};
template<typename _Ty,
typename enable_if< is_base_of<OverVoid, remove_all_pointers<_Ty>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<_Ty>::type::isOverVoid()<<endl;
}
};
int main(){
Move<Meta***> z;
Move<Meta**> w;
Move<Meta*> x;
Move<Meta> y;
}
it displays the following error
Info: Internal Builder is used for build
g++ -std=c++0x -std=c++11 -std=gnu++11 -O0 -g3 -Wall -c -fmessage-length=0 -o "src\\helllo_world.o" "..\\src\\helllo_world.cpp"
In file included from ..\src\helllo_world.cpp:1:0:
..\src\Move.h:54:111: error: type/value mismatch at argument 2 in template parameter list for 'template<class, class> struct std::is_base_of'
template<typename _Ty,class = typename std::enable_if<std::is_base_of<OverVoid, remove_all_pointers<_Ty>::type>::value>::type>
^
..\src\Move.h:54:111: note: expected a type, got 'remove_all_pointers<T>::type'
..\src\Move.h:54:119: error: template argument 1 is invalid
template<typename _Ty,class = typename std::enable_if<std::is_base_of<OverVoid, remove_all_pointers<_Ty>::type>::value>::type>
^
..\src\helllo_world.cpp: In function 'int main()':
..\src\helllo_world.cpp:31:14: error: template argument 2 is invalid
Move<Meta***> z;
^
..\src\helllo_world.cpp:32:13: error: template argument 2 is invalid
Move<Meta**> w;
^
..\src\helllo_world.cpp:33:12: error: template argument 2 is invalid
Move<Meta*> x;
^
..\src\helllo_world.cpp:34:11: error: template argument 2 is invalid
Move<Meta> y;
^
..\src\helllo_world.cpp:31:16: warning: unused variable 'z' [-Wunused-variable]
Move<Meta***> z;
^
..\src\helllo_world.cpp:32:15: warning: unused variable 'w' [-Wunused-variable]
Move<Meta**> w;
^
..\src\helllo_world.cpp:33:14: warning: unused variable 'x' [-Wunused-variable]
Move<Meta*> x;
^
..\src\helllo_world.cpp:34:13: warning: unused variable 'y' [-Wunused-variable]
Move<Meta> y;
^
You are missing some typenames and have the class template Move definition repeated three times.
Th below code works:
#include <iostream>
#include <type_traits>
using namespace std;
template <typename T> class remove_all_pointers{
public:
typedef T type;
};
template <typename T> class remove_all_pointers<T*>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* const>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* volatile>{
public:
typedef typename remove_all_pointers<T>::type type;
};
template <typename T> class remove_all_pointers<T* const volatile >{
public:
typedef typename remove_all_pointers<T>::type type;
};
class OverVoid{
public:
static bool isOverVoid (){
return true;
}
virtual ~OverVoid(){
}
};
class Meta: public OverVoid{
};
class Physical{
public:
};
template<typename T, typename = typename std::enable_if<std::is_base_of<OverVoid, typename remove_all_pointers<T>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<T>::type::isOverVoid()<<endl;
}
};
/*
template<typename T,typename = typename std::enable_if<std::is_base_of<OverVoid, typename remove_all_pointers<T>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<T>::type::isOverVoid()<<endl;
}
};
template<typename T, typename = typename std::enable_if<std::is_base_of<OverVoid, typename remove_all_pointers<T>::type>::value>::type>
class Move{
public:
Move()
{
cout<<"### "<<remove_all_pointers<T>::type::isOverVoid()<<endl;
}
};
*/
int main(){
Move<Meta***> z;
Move<Meta**> w;
Move<Meta*> x;
Move<Meta> y;
}