🚀 go-pugleaf

HASDI RODZMANN HASHIM (hasdi@news-server.engin.umich.edu) wrote:
[snip]
: The way I understand it, type-conversion is to transform the bits of one
: variable so that it is representable as the type to be converted into. eg. 
: (int)my_float. type-casting doesn't transform the bits at all, but force
: the compiler to treat that variable as the specified type... which is
: highly unportable. Why would anyone want to typecast then? Can somebody
: clarify this for me? 

Sure.  You typecast when you know better than the compiler.  For example,
without typecasting, malloc() would need to have a version for char *,
int *, and whatnot, and allocating memory for a user-defined structure
would not be possible.  As it is, it returns a void * which is explicitly
or implicitly cast to the correct type.  A more dangerous (but nonetheless
oft-seen) use is to enable you to code assumptions on data.  For instance,
if you have 4 chars that you know to be actually int, like so:

char really_an_int[4];

you can:

int x = *(int *)really_an_int;

Mind you, this is stinking code, but it does get used.