initial import of the C runtime

src/runtime/c/gu/enum.h

@@ -0,0 +1,35 @@
+#ifndef GU_ENUM_H_
+#define GU_ENUM_H_
+
+#include <gu/mem.h>
+
+typedef struct GuEnum GuEnum;
+
+struct GuEnum {
+	void (*next)(GuEnum* self, void* to, GuPool* pool);
+};
+
+void
+gu_enum_next(GuEnum* en, void* to, GuPool* pool);
+
+#ifdef GU_GNUC
+
+#define gu_next(ENUM, T, POOL)						\
+	({								\
+		T gu_next_tmp_;						\
+		gu_enum_next((ENUM), &gu_next_tmp_, (POOL));		\
+		gu_next_tmp_;						\
+	})
+#else
+static inline void*
+gu_enum_next_(GuEnum* en, void* to, GuPool* pool)
+{
+	gu_enum_next(en, to, pool);
+	return to;
+}
+#define gu_next(ENUM, T, POOL)			\
+	(*(T*)gu_enum_next_((ENUM), &(T){0}, (POOL)))
+
+#endif
+
+#endif /* GU_ENUM_H_ */