Class ConstructorStats

tests/constructor_stats.h:75–213

#include <unordered_map>

class ConstructorStats {
protected:
    std::unordered_map<void *, int> _instances; // Need a map rather than set because members can
                                                // shared address with parents
    std::list<std::string> _values;             // Used to track values
                                                // (e.g. of value constructors)
public:
    int default_constructions = 0;
    int copy_constructions = 0;
    int move_constructions = 0;
    int copy_assignments = 0;
    int move_assignments = 0;

    void copy_created(void *inst) {
        created(inst);
        copy_constructions++;
    }

    void move_created(void *inst) {
        created(inst);
        move_constructions++;
    }

    void default_created(void *inst) {
        created(inst);
        default_constructions++;
    }

    void created(void *inst) { ++_instances[inst]; }

    void destroyed(void *inst) {
        if (--_instances[inst] < 0) {
            throw std::runtime_error("cstats.destroyed() called with unknown "
                                     "instance; potential double-destruction "
                                     "or a missing cstats.created()");
        }
    }

    static void gc() {
        // Force garbage collection to ensure any pending destructors are invoked:
#if defined(PYPY_VERSION)
        PyObject *globals = PyEval_GetGlobals();
        PyObject *result = PyRun_String("import gc\n"
                                        "for i in range(2):\n"
                                        "    gc.collect()\n",
                                        Py_file_input,
                                        globals,
                                        globals);
        if (result == nullptr)
            throw py::error_already_set();
        Py_DECREF(result);
#else
        py::module_::import("gc").attr("collect")();
#endif
    }

    int alive() {
        gc();