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9  *   http://www.apache.org/licenses/LICENSE-2.0
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14  * See the License for the specific language governing permissions and
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16  *
17  *****************************************************************************/
18 
19 #pragma once
20 
21 // static assertion. evaluate at compile time. It is very useful like,  STATIC_ASSERT(sizeof(a) == 5);
22 
23 // #define STATIC_ASSERT(expr)   			{ char static_assertion[(expr) ? 1 : -1]; ((void) static_assertion); }	// (void) array;  to remove compiler unused variable warning
24 
25 // more complicated version canbe used anywhere in the source
26 #define STATIC_ASSERT_M(COND,MSG) typedef char static_assertion_##MSG[(!!(COND))*2-1]
27 // token pasting madness:
28 #define STATIC_ASSERT3(X,L) 	STATIC_ASSERT_M(X,static_assertion_at_line_##L)
29 #define STATIC_ASSERT2(X,L) 	STATIC_ASSERT3(X,L)
30 
31 #define STATIC_ASSERT(X)    	STATIC_ASSERT2(X,__LINE__)
32 
33 #define STATIC_ASSERT_POW2(expr)		STATIC_ASSERT(!((expr) & ((expr)-1)))					//  assert  expr  is  2**N
34 #define STATIC_ASSERT_EVEN(expr)		STATIC_ASSERT(!((expr) & 1))
35 #define STATIC_ASSERT_ODD(expr)			STATIC_ASSERT(((expr) & 1))
36 #define STATIC_ASSERT_INT_DIV(a, b) 	STATIC_ASSERT((a) / (b) * (b) == (a))
37 
38