How to test c++ template class with multiple template parameters using gtest? -

i want test template class gtest. read typed_tests in gtest manual , looked @ official example (samples\sample6_unittest.cc) reference. template example has 1 template parameter. but, code has 2 template parameters, how can test it?

i have following code:

// 2 element type template <typename e, typename f> class queuenew { public:     queuenew() {}     void enqueue(const e& element) {}     e* dequeue() {}     f size() const      {         return (f)123;     } }; 

for wrote test code below:

template <class e, class f> queuenew<e, f>* createqueue();  template <> queuenew<int, int>* createqueue<int, int>() {     return new queuenew < int, int > ; } template <> queuenew<char, char>* createqueue<char, char>() {     return new queuenew < char, char > ; }  template <class e, class f> class queuetestnew;  template <class e> class queuetestnew<e, int> : public testing::test { protected:     queuetestnew() : queue(createqueue<e, int>()){}     virtual ~queuetestnew(){ delete queue; }     queuenew<e, int>* const queue; };  template <class e> class queuetestnew<char, e> : public testing::test { protected:     queuetestnew() : queue(createqueue<char, e>()){}     virtual ~queuetestnew(){ delete queue; }     queuenew<char, e>* const queue; };  // list of types want test. typedef ::testing::types <char, int> implementations;  typed_test_case(queuetestnew, implementations);  typed_test(queuetestnew, defaultconstructor) {     expect_eq(123u, this->queue->size()); } 

but when building, error:

error c2976: 'queuetestnew' : few template arguments see declaration of 'queuetestnew' ... 

i think test template method gtest wrong, how should this?

a trick make gtest see single type parameter, nested types. this, can define templated structure such as:

template <typename a, typename b> struct typedefinitions {   typedef typename mya;   typedef typename b myb; }; 

which can pass typed-test fixture:

template <class t> class queuetestnew : public testing::test { protected:   queuetestnew() : queue(createqueue<typename t::mya, typename t::myb>()){}   virtual ~queuetestnew(){ delete queue; }   queuenew<typename t::mya, typename t::myb>* const queue; };  // list of types want test. typedef ::testing::types <typedefinitions<char,char>,                           typedefinitions<int,int> > implementations;  typed_test_case(queuetestnew, implementations);  typed_test(queuetestnew, defaultconstructor) {   typename typeparam::mya somea; // if need access subtypes in test    expect_eq(123u, this->queue->size()); }