Put CMPLX* macros under ISO C11

diff --git a/math/complex.h b/math/complex.h
index 50701f6115f50f3c4aa9f51c7f8101df7504fc5e..a7c911dfdb53e84e3b0b6230b32a8ec1350e7d64 100644 (file)
--- a/math/complex.h
+++ b/math/complex.h
@@ -52,7 +52,7 @@ __BEGIN_DECLS
 #undef I
 #define I _Complex_I
 
-#if defined(__clang__)
+#if defined __USE_ISOC11 && defined __clang__
 /* Clang casts types to _Complex instead of using __builtin_complex.  */
 #define __CMPLX(x, y, t) (+(_Complex t){(t)(x), (t)(y)})
 #define CMPLX(x, y) __CMPLX(x, y, double)