Include complex rather than complex.h in C++ contexts
to avoid name clashes e.g. with boost headers that use I as a generic placeholder.
Fixes as suggested by aprokop in that issue ticket.
@@ -86,7 +86,11 @@ lapack_complex_float lapack_make_complex_float( float re, float im );
/* Complex type (double precision) */
#ifndef lapack_complex_double
+#ifndef __cplusplus
#include <complex.h>
+#else
+#include <complex>
+#endif
#define lapack_complex_double double _Complex
#endif
