Use C++11 static assert instead of macro

#include <string.h>

#include "btcore/include/device_class.h"

#include "osi/include/osi.h"

typedef struct _bt_device_class_t {

  uint32_t unused : 2;  // LSBs

// Ensure the internal device class implementation and public one

// have equal size.

COMPILE_ASSERT(sizeof(_bt_device_class_t) == sizeof(bt_device_class_t));

static_assert(sizeof(_bt_device_class_t) == sizeof(bt_device_class_t),

              "Internal and external device class implementation should have "

              "the same size");

// [Major Service Classes]

// (https://www.bluetooth.org/en-us/specification/assigned-numbers/baseband)

#define DUMMY_COUNTER(c) CONCAT(__osi_dummy_, c)

#define DUMMY_PTR DUMMY_COUNTER(__COUNTER__)

// base/macros.h defines a COMPILE_ASSERT macro to the C++11 keyword

// "static_assert" (it undef's COMPILE_ASSERT before redefining it).

// C++ code that includes base and osi/include/osi.h can thus easily default to

// the definition from libbase but we should check here to avoid compile errors.

#ifndef COMPILE_ASSERT

#define COMPILE_ASSERT(COND) \

  typedef int failed_compile_assert[(COND) ? 1 : -1] __attribute__((unused))

#endif  // COMPILE_ASSERT

// Macros for safe integer to pointer conversion. In the C language, data is

// commonly cast to opaque pointer containers and back for generic parameter

// passing in callbacks. These macros should be used sparingly in new code