====== C ======

====== printf format check ======

<code c>extern int my_printf (void *my_object, const char *my_format, ...) __attribute__ ((format (printf, 2, 3)));</code>

====== volatile ======
  * **volatile uint8_t *foo;** -  tells the compiler the memory being pointed to is volatile
    * **uint8_t volatile * p_ledreg = 0x10000000;** - In the above code, the variable p_legreg is a pointer to a volatile 8-bit unsigned register located at address 0x10000000.
  * **uint8_t * volatile foo;** - mark the pointer itself as volatile

====== compile time asserts ======

  * Can be used in local block without compiler warning:
  * Cannot be used outside functions (i.e. header)
<code c>
#define COMPILE_TIME_ASSERT(pred)   switch(0){case 0:case pred:;}   // NOLINT
</code>

  * can be used in headers
  * compiler show warnings if used locally (typedef not used)
<code c>
#ifndef CTASSERT                /* Allow lint to override */
#define CTASSERT(x)             _CTASSERT(x, __LINE__)
#define _CTASSERT(x, y)         __CTASSERT(x, y)
#define __CTASSERT(x, y)        typedef char __assert ## y[(x) ? 1 : -1]
#endif
</code>

======= MAX_VALUE =======

<code c>
#define IS_TYPE_SIGNED(a) ((a-1) < 0)
#define MAX_VALUE_UNSIGNED(a) (((unsigned long long)1 << \
        (sizeof(a) * CHAR_BIT)) - 1)
#define MAX_VALUE_SIGNED(a) (MAX_VALUE_UNSIGNED(a) >> 1)
#define MAX_VALUE(a) (IS_TYPE_SIGNED(a) ? \
        MAX_VALUE_SIGNED(a) : MAX_VALUE_UNSIGNED(a))
</code>        

====== sizeof ======

<code c>
#define member_size(type, member) sizeof(((type *)0)->member)
</code>