x-alloc class function prototypes

include/nickel/xalloc.h

@@ -1,11 +1,25 @@
 #ifndef __NICKEL_XALLOC_H_
 #define __NICKEL_XALLOC_H_
 
+#include <sys/types.h>
+#include <stdlib.h>
+
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* header contents */
+void* ni_xmalloc(size_t size);
+void ni_free(void* ptr);
+
+void* ni_xcalloc(size_t nmemb,size_t size);
+void* ni_xrealloc(void* ptr, size_t size);
+
+char* ni_xstrdup(const char *s);
+char* ni_xstrndup(const char s[], size_t n);
 
 #ifdef __cplusplus
 }