On 11/12/2013 01:38 PM, Ali Çehreli wrote:
On 11/12/2013 01:06 PM, Charles Hixson wrote:
Is there any better way to write the method than:
(cmp doesn't seem to work, and byte arrays don't have an opCmp method.)
int opCmp(ref const B24 b) const
{ for (int i = 0; i < 24; i++)
{ if (bytes[i] < b.bytes[i]) return -1;
if (bytes[i] > b.bytes[i]) return 1;
}
return 0;
} // opCmp
FWIW, the key is a fixed length array of ubyte, but similar structs have
differing lengths. If it's not supported by the system I don't want to
do something like casting the pieces
to ulongs and comparing those rather than the bytes. The added
complexity isn't worth it.
There is std.algorithm.cmp:
import std.algorithm;
struct B24
{
byte[24] bytes;
int opCmp(ref const B24 b) const
{
return bytes[].cmp(b.bytes[]);
}
}
void main()
{
auto a = B24();
auto b = B24();
assert(a == b);
a.bytes[23] = 1;
assert(a > b);
b.bytes[22] = 1;
assert(b > a);
}
Ali
Thank you. That's exactly the answer I was looking for. (
I had tried "return bytes.cmp(b.bytes);" , but it didn't occur to me
that the error meant I should have used a copy? Does this syntax mean
that what's being compared is a dynamic array copy of the original
static array? Even if it is, that's the answer I wanted.
--
Charles Hixson
