On Tuesday, 2 October 2012 at 16:48:34 UTC, Peter Alexander wrote:
Then don't create ranges that use ushort for indexing and
length. There's no need to.
To be clear, I'm suggesting that all random access ranges
should use size_t, and they will not be random access ranges if
they use anything else. Unless someone can give a compelling
reason not to do this, I cannot see anything but benefits.
I don't know, forcing an implementer on size_t is pretty
gratuitous. Why can't he be free to choose his own index type?
Besides, you'll still run into the problem for ranges that use
ulong, such as iota.
Then what about ranges that use ulong? As those wrong too? What
about iota? Wrong?
//----
import std.range;
import std.algorithm;
void main()
{
auto r = assumeSorted(iota(0L, 1L)); //Still DERP!
}
//----
src\phobos\std\range.d(6925): Error: cannot implicitly convert
expression (this._input.length()) of type ulong to uint
src\phobos\std\range.d(7346): Error: template instance
std.range.SortedRange!(Result,"a < b") error instantiating
//----
And this time, you can't blame me for doing fishy code, it's all
in phobos.
The end problem is this.
//----
struct S(R)
{
//...
auto opIndex(some_type n)
{
return r[r];
}
}
//----
Regardless of what you do, you will encounter problems at the
"boundaries" or S.opIndex. Either for calling it, because
some_type is too small, either for implementing it, because
some_type is too big.
The fact that both uint, ulong and size_t are valid indexers for
range means ANYTHING in Phobos can break.
The trait I'm proposing should enable support for uint, ulong and
size_t, and every other type as an added bonus.
