Add example of passing struct to task function

.gitignore

@@ -0,0 +1 @@
+example

example.c

@@ -14,12 +14,22 @@
 #include <stdio.h>
 #include <pthread.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include "thpool.h"
 
+typedef struct
+{
+  int id;
+} workload;
+
 void task(void *arg){
 	printf("Thread #%u working on %d\n", (int)pthread_self(), (int) arg);
 }
 
+void task_via_struct(void *arg){
+	workload wl = *((workload *)arg);
+	printf("Thread #%u working on %d\n", (int)pthread_self(), wl.id);
+}
 
 int main(){
 
@@ -33,8 +43,22 @@ int main(){
 	};
 
 	thpool_wait(thpool);
+
+	puts("Adding 40 tasks to threadpool using struct");
+	workload *instructions[40];
+	for (i=0; i<40; i++){
+		instructions[i]= malloc(sizeof(workload));
+		instructions[i]->id=i;
+		thpool_add_work(thpool, task_via_struct, instructions[i]);
+	};
+
+	thpool_wait(thpool);
+
 	puts("Killing threadpool");
 	thpool_destroy(thpool);
-
+
+	for(i=0;i<40;i++){
+		free(instructions[i]);
+	}
 	return 0;
 }