On 8/10/16 2:08 PM, Lodovico Giaretta wrote:
I'm probably missing something stupid but...
Why on earth do the two loops in main print a different result?
It looks like the foreach lowering is ignoring my definition of front...
=====================================================
import std.stdio, std.container.array;
struct RangeWrapper(Range)
{
Range range;
alias range this;
auto front()
{
return range.front + 1;
}
}
auto rangeWrapper(Range)(auto ref Range range)
{
return RangeWrapper!Range(range);
}
void main()
{
Array!int array;
array.insertBack(3);
foreach (i; rangeWrapper(array[]))
writeln(i); // prints 3, which is wrong
// isn't the above foreach equivalent to the following loop ?
for (auto r = rangeWrapper(array[]); !r.empty; r.popFront())
writeln(r.front); // correctly prints 4
}
=====================================================
Thank you for your help.
The issue is that it tries using [] on the item to see if it defines a
range-like thing. Since you don't define opSlice(), it automatically
goes to the subrange.
This breaks for int[] as well as Array.
If I add opSlice to your code (and return this) it works.
This is definitely a bug, it should try range functions before opSlice.
Please file.
-Steve
