Array initialization quiz

[Ali Çehreli]

On 11/30/2011 10:17 AM, Xinok wrote:
 > On 11/30/2011 11:46 AM, Steven Schveighoffer wrote:
 >>
 >> foreach(_i; ubyte.min..ubyte.max + 1){
 >> ubyte i = cast(ubyte)_i;
 >> }
 >>
 >> But my point was, foreach over a range gives me all the elements in a
 >> range, regardless of how the underlying loop is constructed. The
 >> limitation by the compiler is artificial.
 >>
 >> I remember at one point there was someone who had actual code that
 >> resulted in a loop for ubytes, or was trying to figure out how to
 >> foreach over all possible ubyte values.
 >>
 >> -Steve
 >
 > It shouldn't be. The compiler should be smart enough to inline the
 > function and optimize the typecast to something like this:
 >
 > void main(string[] args){
 > foreach(_i; ubyte.min .. ubyte.max + 1)
 > writeln(*cast(ubyte*)&_i);
 > }
 >
 > This would actually be faster since you don't have to iterate two
 > variables.

But variables may be implemented on CPU registers and be fast. That is 
easy to do with Steven's code and cast above. In your code, taking the 
address of _i would put _i in memory. (Unless the compiler has an 
optimization for that. Too lazy to check. :()

Also, *cast(ubyte*)&_i works only on little endian systems, right? But 
you meant that the compiler should take care of endianness as well.

Ali