Examples/test-suite/infinity.i

%module infinity

/*  C99 defines INFINITY
    Because INFINITY may be defined by compiler built-ins, we can't use #define.
    Instead, expose the variable MYINFINITY and then use %rename to make it INFINITY in the scripting language.
*/
%rename(INFINITY) MYINFINITY;

%{
#include <math.h>

/* C99 math.h defines INFINITY. If not available, this is the fallback. */
#if !defined(INFINITY)
	#if defined(_MSC_VER)
		union MSVC_EVIL_FLOAT_HACK
		{
			unsigned __int8 Bytes[4];
			float Value;
		};
		const union MSVC_EVIL_FLOAT_HACK INFINITY_HACK = {{0x00, 0x00, 0x80, 0x7F}};
		#define INFINITY (INFINITY_HACK.Value)
		#define INFINITY_NO_CONST
	#endif

	#ifdef __GNUC__
		#define INFINITY (__builtin_inf())
	#elif defined(__clang__)
		#if __has_builtin(__builtin_inf)
			#define INFINITY (__builtin_inf())
		#endif
	#endif

	#ifndef INFINITY
		#define INFINITY (1e1000)
	#endif
#endif

#ifdef INFINITY_NO_CONST
/* To void: error C2099: initializer is not a constant */
double MYINFINITY = 0.0;
void initialise_MYINFINITY(void) {
  MYINFINITY = INFINITY;
}
#else
const double MYINFINITY = INFINITY;
void initialise_MYINFINITY(void) {
}
#endif

float use_infinity(float inf_val)
{
    return inf_val;
}
%}

/* This will allow us to bind the real INFINITY value through SWIG via MYINFINITY. Use %rename to fix the name. */
const double MYINFINITY = INFINITY;
void initialise_MYINFINITY(void);
/* Use of float is intentional because the original bug was in the float conversion due to overflow checking. */
float use_infinity(float inf_val);