{

static int default_construction_count;

static int copy_construction_count;

static int move_construction_count;

static int destruction_count;

int id;

static void reset_counts()

{

default_construction_count = 0;

copy_construction_count = 0;

move_construction_count = 0;

destruction_count = 0;

}

static int construction_count()

{

return default_construction_count + copy_construction_count + move_construction_count;

}

static int active_count()

{

return construction_count() - destruction_count;

}

counted() : id(default_construction_count++) {}

counted(const counted& other) : id(other.id) { ++copy_construction_count; }

counted(counted&& other) : id(other.id) { ++move_construction_count; other.id = -1; }

~counted() { ++destruction_count; }