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Why this macro accepts a template with 1 parameter and refuses a template with 2 parameters?


I'm working with CPPUNIT 1.12.1.

It has those macro defined:

#define CPPUNIT_TEST_SUITE_ADD_TEST( test ) \
      context.addTest( test )

#define CPPUNIT_TEST( testMethod )                        \
    CPPUNIT_TEST_SUITE_ADD_TEST(                           \
        ( new CPPUNIT_NS::TestCaller<TestFixtureType>(    \
                  context.getTestNameFor( #testMethod),   \
                  &TestFixtureType::testMethod,           \
                  context.makeFixture() ) ) )

I want to add many tests to the same test suite using templates (as CPPUNIT works, every test must be a void function, so using template makes it possible to call the same void function with different "parameters"...).

This works perfectly:

class MyTestSuite1 : public CPPUNIT_NS::TestFixture
{
    CPPUNIT_TEST_SUITE(MyTestSuite1);
    CPPUNIT_TEST(doTest<false>);
    CPPUNIT_TEST(doTest<true>);
    CPPUNIT_TEST_SUITE_END();

    template<bool param> void doTest() { /* test here */ }
};
CPPUNIT_TEST_SUITE_REGISTRATION(MyTestSuite1);

while this does not:

class MyTestSuite2 : public CPPUNIT_NS::TestFixture
{
    CPPUNIT_TEST_SUITE(MyTestSuite2);
    CPPUNIT_TEST(doTest<false,false>);
    CPPUNIT_TEST(doTest<true,false>);
    CPPUNIT_TEST_SUITE_END();

    template<bool param1,bool param2> void doTest() { /* test here */ }
};
CPPUNIT_TEST_SUITE_REGISTRATION(MyTestSuite2);

Compiler (Visual Studio 2015) reports:

1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(20): warning C4002: too many actual parameters for macro 'CPPUNIT_TEST' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(21): warning C4002: too many actual parameters for macro 'CPPUNIT_TEST' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(20): error C2059: syntax error: ')' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(21): error C2059: syntax error: ')' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(22): error C2143: syntax error: missing ';' before '}' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(22): error C2065: 'namer': undeclared identifier 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(22): error C2065: 'factory': undeclared identifier 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(22): error C2059: syntax error: ')' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(29): error C2143: syntax error: missing ';' before '{' 1>b:\dev\vobs_diabeloop\private\tst\regulation\cppunit\hyper_ftac3\test.cpp(30): error C2143: syntax error: missing ';' before '{'

Why is that? How could the macro handle correctly 1 template parameter, but fails for two? Any idea how I could easily have it compile and work?

Edit: Already tried CPPUNIT_TEST((doTest<false,false>)); without success (getting error C2143: syntax error: missing ';' before ')')


Solution

  • CPPUNIT_TEST(doTest<false,false>);
    

    This one doesn't work because macro thinks you are passing 2 macro parameters: doTest<false and false>.


    CPPUNIT_TEST((doTest<false,false>));
    

    This doesn't work because &TestFixtureType::testMethod will expand to &TestFixtureType::(doTest<false,false>) which is invalid.


    As mentioned by Piotr in comment, you can use this code:

    #define COMMA ,
    class MyTestSuite2 : public CPPUNIT_NS::TestFixture
    {
        CPPUNIT_TEST_SUITE(MyTestSuite2);
        CPPUNIT_TEST(doTest<false COMMA false>);
        CPPUNIT_TEST(doTest<true COMMA  false>);
        CPPUNIT_TEST_SUITE_END();
    
        template<bool param1, bool param2> void doTest() { /* test here */ }
    };
    CPPUNIT_TEST_SUITE_REGISTRATION(MyTestSuite2);
    

    Because pre-processor sees that you want to pass 1 parameter