My initial suspicion was that there was a circular dependency in my code and went through Resolve header include circular dependencies. But this hasn’t resolved my compilation errors. Here is the code with 3 classes – A, G & N.
//A.h
#ifndef A_H_
#define A_H_
class com::xxxx::test::G;
namespace com { namespace xxxx { namespace test {
class A {
public:
A();
~A();
void method1(void);
private:
G* g;
};
} } }
#endif /* A_H_ */
//A.cpp
#include "A.h"
#include "G.h"
namespace com { namespace xxxx { namespace test {
A::A() {
g = new com::xxxx::test::G();
}
A::~A() {
delete g;
}
void A::method1() {
g->method2(*this);
}
} } }
//G.h
#ifndef G_H_
#define G_H_
class com::xxxx::test::A;
namespace com { namespace xxxx { namespace test {
class G {
public:
void method2(const A&);
};
} } }
#endif /* G_H_ */
//G.cpp
#include "N.h"
namespace com { namespace xxxx { namespace test {
void G::method2(const A& a) {
N n(a, *this);
}
} } }
//N.h
#ifndef N_H_
#define N_H_
#include "A.h"
#include "G.h"
namespace com { namespace xxxx { namespace test {
class N {
public:
N(const A& obj1, const G& obj2) : a(obj1), g(obj2) {}
void method3(void);
private:
A a;
G g;
};
} } }
#endif /* N_H_ */
I am getting about 10 compilation errors in A.h and A.cpp I am listing the compilation errors below:
./src/A.h:11: error: 'com' has not been declared
../src/A.h:25: error: ISO C++ forbids declaration of 'G' with no type
../src/A.h:25: error: invalid use of '::'
../src/A.h:25: error: expected ';' before '*' token
../src/A.cpp: In constructor 'com::xxxx::test::A::A()':
../src/A.cpp:16: error: 'g' was not declared in this scope
../src/A.cpp: In destructor 'com::xxxx::test::A::~A()':
../src/A.cpp:20: error: 'g' was not declared in this scope
../src/A.cpp: In member function 'void com::xxxx::test::A::method1()':
../src/A.cpp:24: error: 'g' was not declared in this scope
What could be the mistake in the above code?
Thank you in advance,
Regards,
Raghava.
The forward declaration
is illegal. Members of a namespace must be declared within it.
Also, as Kenny says, namespaces aren’t used like this in C++. Unless your project is distributed as a library or is of reasonably large size (dozens of files minimum), you probably don’t need your own namespace.