Define FUNCTION_CAST in a common header

7 files changed, 15 insertions, 46 deletions

diff --git a/examples/alconvolve.c b/examples/alconvolve.c
index 8979e7a3..93fd2eb4 100644
--- a/examples/alconvolve.c
+++ b/examples/alconvolve.c
@@ -84,17 +84,6 @@ static LPALGETAUXILIARYEFFECTSLOTIV alGetAuxiliaryEffectSlotiv;
 static LPALGETAUXILIARYEFFECTSLOTF alGetAuxiliaryEffectSlotf;
 static LPALGETAUXILIARYEFFECTSLOTFV alGetAuxiliaryEffectSlotfv;
 
-/* C doesn't allow casting between function and non-function pointer types, so
- * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
- * still needs to use a normal cast and live with the warning (C++ is fine with
- * a regular reinterpret_cast).
- */
-#if __STDC_VERSION__ >= 199901L
-#define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
-#else
-#define FUNCTION_CAST(T, ptr) (T)(ptr)
-#endif
-
 
 /* This stuff defines a simple streaming player object, the same as alstream.c.
  * Comments are removed for brevity, see alstream.c for more details.
diff --git a/examples/alhrtf.c b/examples/alhrtf.c
index b8fc287f..d878870e 100644
--- a/examples/alhrtf.c
+++ b/examples/alhrtf.c
@@ -170,7 +170,7 @@ int main(int argc, char **argv)
     }
 
     /* Define a macro to help load the function pointers. */
-#define LOAD_PROC(d, T, x)  ((x) = (T)alcGetProcAddress((d), #x))
+#define LOAD_PROC(d, T, x)  ((x) = FUNCTION_CAST(T, alcGetProcAddress((d), #x)))
     LOAD_PROC(device, LPALCGETSTRINGISOFT, alcGetStringiSOFT);
     LOAD_PROC(device, LPALCRESETDEVICESOFT, alcResetDeviceSOFT);
 #undef LOAD_PROC
diff --git a/examples/allatency.c b/examples/allatency.c
index 3b141ac0..ab4a4ebc 100644
--- a/examples/allatency.c
+++ b/examples/allatency.c
@@ -51,17 +51,6 @@ static LPALGETSOURCEI64SOFT alGetSourcei64SOFT;
 static LPALGETSOURCE3I64SOFT alGetSource3i64SOFT;
 static LPALGETSOURCEI64VSOFT alGetSourcei64vSOFT;
 
-/* C doesn't allow casting between function and non-function pointer types, so
- * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
- * still needs to use a normal cast and live with the warning (C++ is fine with
- * a regular reinterpret_cast).
- */
-#if __STDC_VERSION__ >= 199901L
-#define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
-#else
-#define FUNCTION_CAST(T, ptr) (T)(ptr)
-#endif
-
 /* LoadBuffer loads the named audio file into an OpenAL buffer object, and
  * returns the new buffer ID.
  */
diff --git a/examples/alloopback.c b/examples/alloopback.c
index 844efa74..7513458b 100644
--- a/examples/alloopback.c
+++ b/examples/alloopback.c
@@ -149,7 +149,7 @@ int main(int argc, char *argv[])
     }
 
     /* Define a macro to help load the function pointers. */
-#define LOAD_PROC(T, x)  ((x) = (T)alcGetProcAddress(NULL, #x))
+#define LOAD_PROC(T, x)  ((x) = FUNCTION_CAST(T, alcGetProcAddress(NULL, #x)))
     LOAD_PROC(LPALCLOOPBACKOPENDEVICESOFT, alcLoopbackOpenDeviceSOFT);
     LOAD_PROC(LPALCISRENDERFORMATSUPPORTEDSOFT, alcIsRenderFormatSupportedSOFT);
     LOAD_PROC(LPALCRENDERSAMPLESSOFT, alcRenderSamplesSOFT);
diff --git a/examples/almultireverb.c b/examples/almultireverb.c
index 447216d1..a77cc59e 100644
--- a/examples/almultireverb.c
+++ b/examples/almultireverb.c
@@ -92,17 +92,6 @@ static LPALGETAUXILIARYEFFECTSLOTIV alGetAuxiliaryEffectSlotiv;
 static LPALGETAUXILIARYEFFECTSLOTF alGetAuxiliaryEffectSlotf;
 static LPALGETAUXILIARYEFFECTSLOTFV alGetAuxiliaryEffectSlotfv;
 
-/* C doesn't allow casting between function and non-function pointer types, so
- * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
- * still needs to use a normal cast and live with the warning (C++ is fine with
- * a regular reinterpret_cast).
- */
-#if __STDC_VERSION__ >= 199901L
-#define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
-#else
-#define FUNCTION_CAST(T, ptr) (T)(ptr)
-#endif
-
 
 /* LoadEffect loads the given initial reverb properties into the given OpenAL
  * effect object, and returns non-zero on success.
diff --git a/examples/alreverb.c b/examples/alreverb.c
index 0d62e210..11a3ac6b 100644
--- a/examples/alreverb.c
+++ b/examples/alreverb.c
@@ -67,17 +67,6 @@ static LPALGETAUXILIARYEFFECTSLOTIV alGetAuxiliaryEffectSlotiv;
 static LPALGETAUXILIARYEFFECTSLOTF alGetAuxiliaryEffectSlotf;
 static LPALGETAUXILIARYEFFECTSLOTFV alGetAuxiliaryEffectSlotfv;
 
-/* C doesn't allow casting between function and non-function pointer types, so
- * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
- * still needs to use a normal cast and live with the warning (C++ is fine with
- * a regular reinterpret_cast).
- */
-#if __STDC_VERSION__ >= 199901L
-#define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
-#else
-#define FUNCTION_CAST(T, ptr) (T)(ptr)
-#endif
-
 
 /* LoadEffect loads the given reverb properties into a new OpenAL effect
  * object, and returns the new effect ID. */
diff --git a/examples/common/alhelpers.h b/examples/common/alhelpers.h
index 3752d218..34f73864 100644
--- a/examples/common/alhelpers.h
+++ b/examples/common/alhelpers.h
@@ -18,6 +18,19 @@ void CloseAL(void);
 int altime_get(void);
 void al_nssleep(unsigned long nsec);
 
+/* C doesn't allow casting between function and non-function pointer types, so
+ * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
+ * still needs to use a normal cast and live with the warning (C++ is fine with
+ * a regular reinterpret_cast).
+ */
+#if __STDC_VERSION__ >= 199901L
+#define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
+#elif defined(__cplusplus)
+#define FUNCTION_CAST(T, ptr) reinterpret_cast<T>(ptr)
+#else
+#define FUNCTION_CAST(T, ptr) (T)(ptr)
+#endif
+
 #ifdef __cplusplus
 } // extern "C"
 #endif