// filename:c2011-6-7-3-ex.c
// original examples and/or notes:
// 		(c) ISO/IEC JTC1 SC22 WG14 N1570, April 12, 2011
// 			C2011 6.7.3 Type qualifiers
// compile and output mechanism:
// 		(c) Ogawa Kiyoshi, kaizen@gifu-u.ac.jp, December.xx, 2013
// compile errors and/or wornings:
// 		(c) Apple LLVM version 4.2 (clang-425.0.27) (based on LLVM 3.2svn)
// 			Target: x86_64-apple-darwin11.4.2 //Thread model: posix
// 		(c) LLVM 2003-2009 University of Illinois at Urbana-Champaign.
#include <stdio.h>
#include <stdatomic.h> 
int main(void)
{
// Example 1
	extern const volatile int real_time_clock;
// Example 2
	const struct s { int mem; } cs = { 1 };
	
struct s ncs; // the object ncs is modifiable
typedef int A[2][3];
const A a = {{4, 5, 6}, {7, 8, 9}}; // array of array of const int
int *pi;
const int *pci;
	ncs = cs; // valid
	printf(" %d ", ncs.mem);
// cs = ncs; // violates modifiable lvalue constraint for =
//	c2011-6-7-3-ex.c:25:4: error: read-only variable is not assignable
//	cs = ncs; // violates modifiable lvalue constraint for =
//	~~ ^
	pi = &ncs.mem; // valid
	printf("%d ", pi);
	pi = &cs.mem; // violates type constraints for =
	printf("%d ", pi);
// c2011-6-7-3-ex.c:30:4: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]
// pi = &cs.mem; // violates type constraints for =
//    ^	
	pci = &cs.mem; // valid
		printf("%d ", pci);
	pi = a[0]; // invalid: a[0] has type ‘‘const int *’’
		printf("%d ", pi);
//	c2011-6-7-3-ex.c:32:5: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]
//  pi = a[0]; // invalid: a[0] has type ‘‘const int *’’
//     ^
	// Example 3
	_Atomic volatile int *p;
return printf("6.7.3 Type qualifiers %d \n",ncs);	
}
// gcc output may be
// 1 1580133072 1580133088 1580133088 1580133040 6.7.3 Type qualifiers 1