Put CMPLX* macros under ISO C11

diff --git a/math/complex.h b/math/complex.h
index 3e4ea051ec3864bcd46a8ab9ba59ab27d1d2f28e..870c0689b0aef15c3c92c5d7ed8107db4b4b3629 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)