Add graph references

references/igraph-1.0.1/vendor/f2c/signal1.h

@@ -0,0 +1,35 @@
+/* You may need to adjust the definition of signal1 to supply a */
+/* cast to the correct argument type.  This detail is system- and */
+/* compiler-dependent.   The #define below assumes signal.h declares */
+/* type SIG_PF for the signal function's second argument. */
+
+/* For some C++ compilers, "#define Sigarg_t ..." may be appropriate. */
+
+#include <signal.h>
+
+#ifndef Sigret_t
+#define Sigret_t void
+#endif
+#ifndef Sigarg_t
+#ifdef KR_headers
+#define Sigarg_t
+#else
+#define Sigarg_t int
+#endif
+#endif /*Sigarg_t*/
+
+#ifdef USE_SIG_PF	/* compile with -DUSE_SIG_PF under IRIX */
+#define sig_pf SIG_PF
+#else
+typedef Sigret_t (*sig_pf)(Sigarg_t);
+#endif
+
+#define signal1(a,b) signal(a,(sig_pf)b)
+
+#ifdef __cplusplus
+#define Sigarg ...
+#define Use_Sigarg
+#else
+#define Sigarg Int n
+#define Use_Sigarg n = n	/* shut up compiler warning */
+#endif