Examples/test-suite/constant_expr_c.i

%module constant_expr_c;
/* Tests of constant expressions (C version). */

%inline %{
#if defined __GNUC__ && __GNUC__ >= 5
// Suppress warnings about constant comparisons.
# pragma GCC diagnostic ignored "-Wbool-compare"
#endif

#if defined(_MSC_VER)
  #pragma warning(disable : 4804) // warning C4804: '<': unsafe use of type 'bool' in operation
#endif

/* % didn't work in SWIG 1.3.40 and earlier. */
const int X = 123%7;
#define FOO 12 % 9
double d_array[12 % 9];

/* `<` and `>` in constant expressions caused parse errors before SWIG 4.1.0.
 * They're now supported if inside parentheses (and with some restrictions
 * on the LHS of `<`.
 */

// Testcase from https://github.com/swig/swig/issues/635
#define TEST_A 1
#define TEST_B 2
#define TEST_C (TEST_A < TEST_B)
#define TEST_D (TEST_A > TEST_B)
// These have been supported since 1.3.41.
#define TEST_E (TEST_A <= TEST_B)
#define TEST_F (TEST_A >= TEST_B)
// For completeness
#define TEST_G (TEST_A == TEST_B)
#define TEST_H (TEST_A != TEST_B)

// No warning
#if (TEST_A < TEST_B)
#define TEST_I 1
#else
#define TEST_I 0
#endif

/* Regression test for bug with losing parentheses around < and > operators,
 * fixed in 4.2.0.
 */
#define XX (2<(2<2))
#define YY (2>(2>2))
int xx() { return (int)(XX); }
int yy() { return (int)(YY); }

/* sizeof didn't work on an expression before SWIG 4.1.0 except for cases where
 * the expression was in parentheses and looked syntactically like a type (so
 * sizeof(X) worked because X could be a type syntactically).
 */
const int s1a = sizeof(X); /* worked before 4.1.0 */
//const int s1b = sizeof X; /* not currently supported */
const int s2a = sizeof("a string" );
const int s2b = sizeof "a string";
const int s3a = sizeof('c');
const int s3b = sizeof('c');
const int s4a = sizeof(L"a wstring");
const int s4b = sizeof L"a wstring";
const int s5a = sizeof(L'C');
const int s5b = sizeof L'C';
const int s6a = sizeof(sizeof(X));
const int s6b = sizeof sizeof(X);
const int s7a = sizeof(3.14);
const int s7b = sizeof 3.14;
const int s8a = sizeof(2.1e-6);
const int s8b = sizeof 2.1e-6;

%}