//-Wall -Wextra -Wpedantic -Wshadow
#include <stdio.h>
#include <stdlib.h>

typedef struct{
char a;
int b;
}TestStruct;

void TestF1( TestStruct s )
{
    printf(" (F1) %c %d\n", s.a, s.b );
}

void TestF2( TestStruct *p_s )
{
    printf(" (F2) %c %d\n", p_s->a, p_s->b );
}

void TestF3( TestStruct *p_s )
{
    TestStruct s = *p_s;
    printf("(F3a) %c %d\n", s.a, s.b );
    s.a = 'd';
    s.b = 231;
    printf("(F3b) %c %d\n", s.a, s.b );
}

void TestF4( TestStruct *p_s )
{
    p_s->a = 'b';
    p_s->b = 321;
}

void TestV( char *p_a, int *p_i )
{
    *p_a = 'c';
    *p_i = 312;
}

int main()
{

    TestStruct tsts;

    tsts.a = 'a';
    tsts.b = 123;

    printf("  (1) %c %d\n", tsts.a, tsts.b );

    TestStruct *p_ts;

    p_ts = &tsts;

    printf("  (2) %c %d\n", p_ts->a, p_ts->b );

    TestF1(tsts);
    TestF1(*p_ts);

    TestF2(&tsts);
    TestF2(p_ts);

    TestF3(&tsts);
    TestF3(p_ts);

    printf("  (3) %c %d\n", tsts.a, tsts.b );
    printf("  (4) %c %d\n", p_ts->a, p_ts->b );

    TestF4( &tsts );

    printf("  (5) %c %d\n", tsts.a, tsts.b );
    printf("  (6) %c %d\n", p_ts->a, p_ts->b );

    tsts.a = 'c';
    tsts.b = 132;

    printf("  (7) %c %d\n", tsts.a, tsts.b );
    printf("  (8) %c %d\n", p_ts->a, p_ts->b );

    TestF4( p_ts );

    printf("  (9) %c %d\n", tsts.a, tsts.b );
    printf(" (10) %c %d\n", p_ts->a, p_ts->b );

    char c = 'a';
    int i = 1;

    printf (" (11) %c %d\n", c, i);

    TestV(&c,&i);

    printf (" (12) %c %d\n", c, i);

    return 0;
}

/*
output:

  (1) a 123
  (2) a 123
 (F1) a 123
 (F1) a 123
 (F2) a 123
 (F2) a 123
(F3a) a 123
(F3b) d 231
(F3a) a 123
(F3b) d 231
  (3) a 123
  (4) a 123
  (5) b 321
  (6) b 321
  (7) c 132
  (8) c 132
  (9) b 321
 (10) b 321
 (11) a 1
 (12) c 312

*/