[Solved] C++ Issues with vector

You did not show the code which adds the Child*s to the vector, but the symptoms you describe provide compelling evidence that you used pointers to some kind of local or temporary objects, which go out of scope (are destroyed) while the vector still holds the pointers. Your program hangs as a result of using … Read more

[Solved] Converting C code to Java [closed]

double* ptr; ptr = (double*)malloc(10*_R_CONST*sizeof(double)+2048); This is the C way of allocating an array dynamically at runtime, the Java equivalent is double[] ptr = new double[10*_R_CONST+256]; (Note that Java does not need the sizeof(double) factor, since it allocates objects, not bytes. For the same reason, the 2048 byte buffer shrinks to 256 doubles.) Similar, the … Read more

[Solved] Does ccall really convert arguments passed by pointer?

This turned out to be either a bug in the core library or a very misguided documentation, depending on the perspective (issue #29850). The behavior of the function unsafe_convert changed from version 0.4 to 0.5, in a way that makes it more flexible than what is currently suggested. According to this commit, unsafe_convert changed from … Read more

[Solved] What does null pointer exception mean in error messages? [duplicate]

Java doesn’t use pointers, but uses references. NullPointerException is a way to say that an attempt is made to send a message (invoke a method) using reference which doesn’t point to any object. It has nothing to do with pointers in the sense of C/C++. solved What does null pointer exception mean in error messages? … Read more