Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/uclibc/90_all_303-c99-complex-ugly-hack.patch
diff -durN gcc-4.3.1.orig/libstdc++-v3/configure gcc-4.3.1/libstdc++-v3/configure
--- gcc-4.3.1.orig/libstdc++-v3/configure	2008-06-10 14:58:43.000000000 +0200
+++ gcc-4.3.1/libstdc++-v3/configure	2008-06-10 14:58:58.000000000 +0200
@@ -39006,6 +39006,9 @@
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <complex.h>
+#ifdef __UCLIBC__
+#error ugly hack to make sure configure test fails here for cross until uClibc supports the complex funcs
+#endif
 int
 main ()
 {