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

Reply via email to