#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>

typedef struct Foo {
  int x;
} Foo;
typedef struct Bar {
  int y;
} Bar;

int main() {
   // Numeric casts are conversions

   int64_t x64 = INT32_MAX;  // assign 4byte to 8byte just works
   x64 +=10;
   int32_t x32 = x64;       // assign 8byte to 4byte will overflow
   printf("wide/narrow integer %" PRId64 " %" PRId32 "\n", x64, x32);


   float f32 = 100.9999;
   int32_t i32 = f32;       // round down

   printf("float to integer %" PRId32 "\n", i32);
   
  int64_t ii64 = INT64_MAX;    
   float ff32 = ii64;         // round because limited precision
   int64_t iii64 = 4000000000; 
   float fff32 = iii64;         // not round because precise enough
   printf("integer to float (rounded) %" PRId64 " %f\n", ii64, ff32);
   printf("integer to float %" PRId64 " %f\n", iii64, fff32);


  // struct casts are compiler errors

  Foo f;
  /* Bar b =  (Bar) f; */     /* compile error */


  // int to pointer (and vice versa) casts are allowed but a bad idea
  // (there are prescribed ways to do this properly. More later)
  int64_t z;
  int64_t* g = &z;
  z = g;      /* compiler warning */
  z = (int64_t) g;  /* no warnings */

  
  // pointer casts are just to get around compiler
  int* p = malloc(sizeof(int));  /* probably a warning */
  int* q = (int*)malloc(sizeof(int));  /* no warnings */
  printf("pointer casts %p %p\n", p, q);
}