On Monday, 21 December 2015 at 23:59:07 UTC, Jay Norwood wrote:
I'm trying to learn ndslice. It puzzles me why t3 compiles ok,
but t4 causes a compiler error in the example below. Should I
be able to slice a struct member that is an array?
import std.stdio;
import std.experimental.ndslice;
import std.experimental.ndslice.iteration: transposed;
struct sample{
ulong [10] core_ctr;
}
struct block{
ulong[60] samples;
}
void main() {
auto a1 = new sample[60];
auto t3 = a1.sliced!(ReplaceArrayWithPointer.no)(3,4,5);
auto b1 = new block;
auto t4 =
b1.samples.sliced!(ReplaceArrayWithPointer.no)(3,4,5);
}
The problem is that t3 is slicing a1 which is a dynamic array,
which is a range, while t4 is trying to slice a static array,
which is not a range.
The ranges primitive popFront mutates the length of the range, so
static arrays cannot be used as ranges. But, if you take a slice
of b1.samples, you can use that as a range.
auto t4 = b1.samples[].sliced!(ReplaceArrayWithPointer.no)(3,4,5);
See the section on ranges on this page for more general info on
ranges: http://dlang.org/overview.html
