Styjun

I'm fairly new to C++, more used to C and python, but google was not my friend this time.

I have a baseclass which implements some googlemock fixtures implemented in 2 generic classes (a baseclass and a parameterized class which derives from that baseclass) and a TEST_P function using the parameterized fixture.
Since the parameterized fixture is used to test 2 implementations I put the fixture-classes and the TEST_P in a baseclass cpp-file (+ hpp file) and the specific parameter-tables in 2 specific cpp files.
This works like a charm.

But... now we want to extend one of the implementations so that it needs a specific implementation of a function which is defined in the generic baseclass. For the other implementation the generic implementation is still correct.

So what I want is to override the generic implementation for only 1 of the 2 test-cpp files.

Initially (without override) I had the following in the hpp:

class MyBaseClass : public ::testing::Test

 protected:
 // boring fixture setup stuff
 virtual void test( void );


class MyParametrizedBaseClass:
 public MyBaseClass, 
 public::testing::WithParmInterface< std:tr1::tuple< /* parameter definition */ > >
 protected:
 // some custom assert method definitions

baseclass.cpp file:

MyBaseClass::test( void )

 cout << "This is the baseclass implementation" << std::endl;


...

TEST_P( MyParametrizedBaseClass, TestName )

 test();
 // other googlemock checks not needed for this question

And in the 2 specific implementations I have just the parameter tables:

std:tr1::tuple< /* parameter definition */ > const TableName[] = 
 //table implementation


INSTANTIATE_TEST_CASE_P( Name, MyParameterizedBaseClass, ::testing::ValuesIn( TableName ) );

Again up to now this works.

Now for ... lets call it impl_1 ... we want test to do the following (this code does not work since the definition for MyParameterizedBaseClass::test is not found):

impl_1.cpp:

void MyParameterizedBaseClass::test( void )

 cout << "This is the impl_1 implementation" << std::endl;

The first thing I did after seeing that the compiler misses the definition of MyParameterizedBaseClass::test was replace MyParameterizedBaseClass with MyBaseClass, but then it sees it as a redefinition (which it indeed is).

So next I googled and found the 'override' key word and adapted the MyParameterizedBaseClass definition so it looks like this:

class MyParametrizedBaseClass:
 public MyBaseClass, 
 public::testing::WithParmInterface< std:tr1::tuple< /* parameter definition */ > >
 protected:
 // some custom assert method definitions
 void test( void ) override;

But when I do that I get the error:
Baseclass.hpp:[linenumber]: error: expected ';' before 'override'
And in the specific implementation for impl_1 it still says that no test function is declared in MyParameterizedBaseClass

And if I (knowing up front that it is wrong) put the ';' before 'override' as suggested, I get: error: ISO C++ forbids declaration of 'override' with no type

Next I removed the 'override' keyword and recompiled.
Now the compiler is satisfied, but the linker fails on impl_2 since there I don't have an implementation of MyParameterizedClass::test.
And that is true, since I want to have the default implementation of test for that.
(To complete the description: Yes it works again if I also implement test for MyParameterizedBaseClass in impl_2.cpp)

So my question is: what am I doing wrong?

Environment: Linux with GCC 4.4.2 (pretty old I know, but that is the version my company has)

Adding declaration in MyParametrizedBaseClass was a good move.
Problem is that you have used C++11 feature override and based on code like this:

std:tr1::tuple< /* parameter definition */ >

(tr1) indicates that you are using C++03 with "technical report one", so keyword override is unknown. That is why compiler complains: error: expected ';' before 'override'

So just remove override keyword and it should be fine.