Hi Phil, Jon
Thanks, now I'm clear with this, assignment doesn't care with type modifier.
Code such as
unsigned int j = 0xffeeddcc;
int i = j;
Both has the same value depending on how them interpreted (is this
assumption correct?)
Because,
printf("%u", i) will be different to printf("%i", i)
- but -
printf("%u", i) wlll be same as printf("%u", j)
Actually why asking this because I often see a pointer to a char* cast
Let me show you with this example.
Consider some structures...
struct a_data {
unsigned char f1[4];
unsigned char f2[6];
unsigned short f3[2];
};
and another struct named b_data, c_data, etc.
Then there is a general function to process all type of structure,
maybe something like this:
int process_data(char *buffer, size_t len);
Then if we cast for example a pointer to a_data struct to a char* as follow:
struct a_data a;
process_data((char*) &a, sizeof(a));
I though since it was cast to char*, the cast is "problem" because
every signed char buffer will have a range CHAR_MIN to CHAR_MAX,
therefore value of CHAR_MAX to UCHAR_MAX will broken (signed char
overflow)
I think process_data() should be declared with
int process_data(unsigned char *buffer, size_t len)
this declaration in seem correct and work for me.
However, now I'm conceptually understand why this works.
Thanks.
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