Using assignment operator overloading to return jobject from class

Question

I am using the JNI invocation API and I would like to be able to perform the following assignment in my main() function:

jobject Myjobject = MyClassInstance;

Where MyClassInstance is an object instance of MyClass.

MyClass.h:

// DEFINE OVERLOADED = OPERATOR //
    jobject operator= (const MyClass &);

MyClass.cpp:

jobject MyClass::operator =(const MyClass & MyInstance)
{
    return MyInstance.jobjectMember;
}

Where jobjectMember is a private jobject member of MyClass.

However, I keep getting the following error during compilation:

error: cannot convert ‘MyClass’ to ‘jobject {aka _jobject*}’ in assignment

Where am I going wrong?

Answer 1

In order jobject Myjobject = MyClassInstance; (which is initialization, not an assignment) to work you need to define a corresponding constructor for jobject class.

class jobject
{
    public: explicit
    jobject(MyClass const & that) {...}

or define conversion operator for MyClass

  class MyClass 
  {
      public: explicit
      operator jobject const &(void) const
      {
          return this->jobjectMember;
      }

  jobject Myjobject{static_cast<jobject const &>(MyClassInstance)};