Sub: add cpp snippets

Body:

==== End ====

snippet/cpp/test_static.c

@@ -1,4 +1,12 @@
 #include <stdio.h>
+#include <stdlib.h>
+
+typedef struct {
+    long long id;
+    char *name;
+    char *desc;
+    int age;
+} Person;
 
 void test () {
     static int num = 0;
@@ -7,14 +15,26 @@ void test () {
 }
 
 void test2() {
+    // static variables defined in fuction can only be visited by this function.
     static int num = 0;
     num++;
     printf("Function test2 has been called %d times\n", num);
 }
 
 int main(int argc, char **argv) {
-    test();
+    // p is on stack, while q is on heap
-    test();
+    Person p;
-    test2();
+    Person *q = (Person *)malloc(sizeof(Person));
-    test2();
+    if (q == NULL) {
+        printf("malloc fails\n");
+        return -1;
+    }
+
+    // test();
+    // test();
+    // test2();
+    // test2();
+    // addr of p: 0x5619048df2d0, addr of q: 0x7fb51f2e19e0
+    printf("addr of p: %p, addr of q: %p\n", p, *q);
+    free(q);
 }

snippet/cpp/test_type.c

@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main(int argc, char **argv) {
+    // there is no type of byte in c
+    // printf("Size of byte: %d bytes\n", sizeof(byte));
+    printf("Size of char: %lu bytes\n", sizeof(char));
+    printf("Size of short: %lu bytes\n", sizeof(short));
+    printf("Size of int: %lu bytes\n", sizeof(int));
+    printf("Size of long: %lu bytes\n", sizeof(long));
+    printf("Size of long int: %lu bytes\n", sizeof(long int));
+    printf("Size of long long: %lu bytes\n", sizeof(long long));
+    return 0;
+}