While there is documentation regarding turning a jstring to a native string (string nativeString = env->GetStringUTFChars(jStringVariable, NULL);
jstring
string nativeString = env->GetStringUTFChars(jStringVariable, NULL);
To cast a jboolean (which may only contain the values JNI_FALSE or JNI_TRUE) to a native bool I would use something like this :
jboolean
JNI_FALSE
JNI_TRUE
bool
(bool)(jboolean == JNI_TRUE)
If perhaps the jboolean isn't coming from the JVM, then testing for jboolean != JNI_FALSE might be considered safer.
jboolean != JNI_FALSE