fix(test): remove the undefined behaviour if the type is not FP

The standard does not define the complex class other than float, double,
and long double. It leaves the implementation on the hands of vendors,
and it could lead to the portability issue or undefined behaviour, which
is not warranted.

Author: amitsingh19975

test/tensor/functions/test_functions_real_imag_conj.cpp

@@ -47,7 +47,7 @@ BOOST_TEST_DECORATOR(
 )
 BOOST_FIXTURE_TEST_CASE_TEMPLATE(test_tensor_dynamic,
     TestTupleType,
-    boost::numeric::ublas::cpp_basic_std_types,
+    boost::numeric::ublas::cpp_basic_std_floating_types,
     boost::numeric::ublas::tuple_fixture_tensor_dynamic<TestTupleType>
 )
 {
@@ -72,15 +72,15 @@ BOOST_FIXTURE_TEST_CASE_TEMPLATE(test_tensor_dynamic,
             auto r00 = complex_tensor_t(n);
 
             tensor_type b = (a+a) / value_type{2};
-            tensor_type r1 = ublas::real( (a+a) / value_type{2}  );
+            tensor_type r1 =  ublas::real( (a+a) / value_type{2}  );
             std::transform(  b.begin(), b.end(), r0.begin(), [](auto const& l){ return std::real( l );  }   );
             BOOST_CHECK_EQUAL_COLLECTIONS(r0.begin(), r0.end(), r1.begin(), r1.end());
 
-            tensor_type r2 = ublas::imag( (a+a) / value_type{2}  );
+            tensor_type r2 =  ublas::imag( (a+a) / value_type{2}  );
             std::transform(  b.begin(), b.end(), r0.begin(), [](auto const& l){ return std::imag( l );  }   );
             BOOST_CHECK_EQUAL_COLLECTIONS(r0.begin(), r0.end(), r2.begin(), r2.end());
 
-            complex_tensor_t r3 = ublas::conj( (a+a) / value_type{2}  );
+            complex_tensor_t r3 =  ublas::conj( (a+a) / value_type{2}  );
             std::transform(  b.begin(), b.end(), r00.begin(), [](auto const& l){ return std::conj( l );  }   );
             BOOST_CHECK_EQUAL_COLLECTIONS(r00.begin(), r00.end(), r3.begin(), r3.end());
 
@@ -118,7 +118,7 @@ BOOST_TEST_DECORATOR(
 )
 BOOST_FIXTURE_TEST_CASE_TEMPLATE(test_tensor_static_rank,
     TestTupleType,
-    boost::numeric::ublas::cpp_basic_std_types,
+    boost::numeric::ublas::cpp_basic_std_floating_types,
     boost::numeric::ublas::tuple_fixture_tensor_static_rank<TestTupleType>
 )
 {
@@ -194,7 +194,7 @@ BOOST_FIXTURE_TEST_CASE_TEMPLATE(test_tensor_static_rank,
 // )
 // BOOST_FIXTURE_TEST_CASE_TEMPLATE(test_tensor_static,
 //     TestTupleType,
-//     boost::numeric::ublas::cpp_basic_std_types,
+//     boost::numeric::ublas::cpp_basic_std_floating_types,
 //     boost::numeric::ublas::tuple_fixture_tensor_static<TestTupleType>
 // )
 // {

test/tensor/utility.hpp

@@ -115,6 +115,10 @@ namespace boost::numeric::ublas{
   // using cpp_std_types = zip<int,float,std::complex<float>>::with_t<layout::first_order, layout::last_order>;
   using cpp_std_types = zip<int,float>::with_t<layout::first_order, layout::last_order>;
 
+  // CPP Standard: The effect of instantiating the template complex for any other type than float, double, and long double is unspecified. 
+  // Implementations may forbid instantiation of such specializations.
+  using cpp_basic_std_floating_types = zip<float>::with_t<layout::first_order, layout::last_order>;
+
   using cpp_basic_std_types = zip<int,float>::with_t<layout::first_order, layout::last_order>;
   using layout_test_types = std::tuple<layout::first_order, layout::last_order>;