C++ memory issue with external library -

i worked commercial company, have lots of internal libraries can reused different project. encountered serious memory issue 1 of library strange.

the source code confidential cannot put here, going mock code describe happened me,

there classes defined in library:

class classb { public:    ...    static classb* acquireinstance(); }; class classa { public:     classb* getb() { return m_pb; }     bool init(classb* pb); private:     classb* m_pb; };  integrated library(static linked) in our project, our code looks this:  void foo() {    ...    classb* pb = classb::acquireinstance();    classa a;    a.init(pb); // step function, m_pb assigned pb, ok inside function.    assert(pb == a.getb()); // failed } 

comments:

the strange thing found: when step init function, address of m_pb (&m_pb) 0x0000ce08, address of m_pb (&a.m_pb) changed 0x0000ce00.

i think byte alignment issue different config between our project , library. not sure,

is there encountered kind of issue before, idea how fix ?

any input appreciated. thank you.