I´ve browsed other similar topics and did not find an answer to my problem...
The code below illustrates the situation. A Base class and a Derived class:
Base.hpp
namespace test {
template<class T>
class Base {
public:
Base();
virtual ~Base();
};
}
Base.cpp
#include "Base.hpp"
namespace test {
template<class T>
Base<T>::Base() {
// TODO Auto-generated constructor stub
};
template<class T>
Base<T>::~Base() {
// TODO Auto-generated destructor stub
};
}
Derived.hpp
namespace test {
class Derived : public Base<int> {
public:
Derived();
virtual ~Derived();
};
} /* namespace aeirtuaccess */
Derived.cpp
#include "Derived.hpp"
namespace test {
Derived::Derived() {
// TODO Auto-generated constructor stub
};
Derived::~Derived() {
// TODO Auto-generated destructor stub
};
}
When I compile this code with Coliru - see it in action here, it works fine, but when I go to my Ubuntu environment using g++ I´m having the following error:
>g++ Base.cpp Derived.cppIn file included from Derived.cpp:2:0:
Derived.hpp:3:28: error: expected template-name before ‘<’ token
class Derived : public Base<int> {
^
Derived.hpp:3:28: error: expected ‘{’ before ‘<’ token
Derived.hpp:3:28: error: expected unqualified-id before ‘<’ token
Derived.cpp:6:18: error: invalid use of incomplete type ‘class test::Derived’
Derived::Derived() {
^
In file included from Derived.cpp:2:0:
Derived.hpp:3:7: error: forward declaration of ‘class test::Derived’
class Derived : public Base<int> {
^
Derived.cpp:11:19: error: invalid use of incomplete type ‘class test::Derived’
Derived::~Derived() {
^
In file included from Derived.cpp:2:0:
Derived.hpp:3:7: error: forward declaration of ‘class test::Derived’
class Derived : public Base<int> {
Is there any difference between the compilers ? Should I use a specific g++ flag or version ? Is there something else that I need to do to fix that in my Ubuntu environment ?
In
Derived.hpp, you need to add:at the top. Otherwise, the compiler doesn't know what
Baserefers to when compiling this file.