cppbind: Refactor to use C++11+ type_traits

CMakeModules/CheckCXXFeatures.cmake

@@ -0,0 +1,30 @@
+check_cxx_source_compiles("
+  #include <utility>
+  #include <type_traits>
+  std::make_index_sequence<0> t;
+  int main() {}" HAVE_STD_INDEX_SEQUENCE
+)
+
+check_cxx_source_compiles("
+  #include <type_traits>
+  std::remove_cv_t<const int> t;
+  int main() {}" HAVE_STD_REMOVE_CV_T
+)
+
+check_cxx_source_compiles("
+  #include <type_traits>
+  std::remove_cvref_t<const int&> t;
+  int main() {}" HAVE_STD_REMOVE_CVREF_T
+)
+
+check_cxx_source_compiles("
+  #include <type_traits>
+  std::enable_if_t<true, int> t;
+  int main() {}" HAVE_STD_ENABLE_IF_T
+)
+
+check_cxx_source_compiles("
+  #include <type_traits>
+  std::bool_constant<true> t;
+  int main() {}" HAVE_STD_BOOL_CONSTANT
+)