Correct warning if used -Wextra

argsparse.h

@@ -109,6 +109,10 @@ void __free_string_array(char** arr, size_t size) {
 
 static void* __sized_malloc(size_t size) {
     void* ptr = malloc(size);
+    if (ptr == NULL) {
+        puts("Out of memory!");
+        abort();
+    }
     memset(ptr, ((int)(unsigned long)NULL), size);
     return (void*)ptr;
 }
@@ -145,6 +149,10 @@ static unsigned char __compile_and_equals_sflag(char* flags, char* str) {
 
 static char* malloc_str(char* str) {
     char* ptr = (char*)malloc((strlen(str)) * sizeof(char) + sizeof(char));
+    if ((void*)ptr == NULL) {
+        puts("Out of memory!");
+        abort();
+    }
     strcpy(ptr, str);
     return ptr;
 }