Getting CppUnit to read application class on netbeans 7.2 - c++

Question

I am learning C++ and CppUnit at the same time, using netbeans 7.2.
I create the following file
#include <cstdlib>
using namespace std;
/*
*
*/
class Subtract{
public:
int minus(int a, int b){
return a-b;
}
};
int main(int argc, char** argv) {
return 0;
}
And then I right-click to generate the following cppunit test file
#include "newtestclass.h"
CPPUNIT_TEST_SUITE_REGISTRATION(newtestclass);
newtestclass::newtestclass() {
}
newtestclass::~newtestclass() {
}
void newtestclass::setUp() {
}
void newtestclass::tearDown() {
}
int Subtract::minus(int a, int b);
void newtestclass::testMinus() {
int a=89;
int b=55;
Subtract subtract;
int result = subtract.minus(a, b);
CPPUNIT_ASSERT_EQUAL(34,result);
}
When I try to run the test, it gives the following errors
g++ -c -g -I. -MMD -MP -MF build/Debug/GNU-MacOSX/tests/tests/newtestclass.o.d -o build/Debug/GNU-MacOSX/tests/tests/newtestclass.o tests/newtestclass.cpp
tests/newtestclass.cpp:25: error: 'Subtract' has not been declared
tests/newtestclass.cpp: In member function 'void newtestclass::testMinus()':
tests/newtestclass.cpp:30: error: 'Subtract' was not declared in this scope
tests/newtestclass.cpp:30: error: expected `;' before 'subtract'
tests/newtestclass.cpp:31: error: 'subtract' was not declared in this scope
make[1]: *** [build/Debug/GNU-MacOSX/tests/tests/newtestclass.o] Error 1
make: *** [.build-tests-impl] Error 2
How do I get this to work properly?

Answer 1

In C++, the convention is to declare the classes and functions in a header file (.h file) and implement them in the source file (.cpp file).
Your Subtract.h file (declarations) should have only this:
class Subtract {
public:
int minus(int a, int b);
};
Your Subtract.cpp file (implementation) should have this:
#include "Subtract.h"
int Subtract::minus(int a, int b)
{
return a-b;
}
Then you #include "Subtract.h" in your newtestclass.cpp file.