Test boolean reference and bump version to v0.7.2

Author: barche

examples/functions.cpp

@@ -329,6 +329,11 @@ JLCXX_MODULE init_test_module(jlcxx::Module& mod)
   mod.method("unmark_boxed", [&] () { jlcxx::unprotect_from_gc(marked_value); });
 
   mod.method("open", [] (const std::string& s) { return s; });
-}
+
+  mod.method("boolref", [] (bool& b)
+  {
+    b = !b;
+  });
+ }
 
 }

include/jlcxx/jlcxx_config.hpp

@@ -15,7 +15,7 @@
 
 #define JLCXX_VERSION_MAJOR 0
 #define JLCXX_VERSION_MINOR 7
-#define JLCXX_VERSION_PATCH 1
+#define JLCXX_VERSION_PATCH 2
 
 // From https://stackoverflow.com/questions/5459868/concatenate-int-to-string-using-c-preprocessor
 #define __JLCXX_STR_HELPER(x) #x

include/jlcxx/type_conversion.hpp

@@ -172,7 +172,9 @@ inline CppT* extract_pointer_nonull(const WrappedCppPtr& p)
 {
   if(p.voidptr == nullptr)
   {
-    throw std::runtime_error("C++ object was deleted");
+    std::stringstream errorstr;
+    errorstr << "C++ object of type " << typeid(CppT).name() << " was deleted";
+    throw std::runtime_error(errorstr.str());
   }
   return extract_pointer<CppT>(p);
 }
@@ -667,7 +669,6 @@ BoxedValue<T> julia_owned(T* cpp_ptr)
 /// Base class to specialize for conversion to Julia
 // C++ wrapped types are in fact always returned as a pointer wrapped in a struct, so to avoid memory management issues with the wrapper itself
 // we always return the wrapping struct by value
-//template<typename T, typename TraitT=mapping_trait<typename std::remove_pointer<typename std::remove_reference<T>::type>::type>>
 template<typename T, typename TraitT=mapping_trait<T>>
 struct ConvertToJulia
 {