On 11-Jun-2015 11:18, w0rp wrote:
A thought just came to me. When I'm implementing foreach for a
container, I'm left with the choice of using a range for a container or
opApply. I've found often that I prefer the ranges, as it's easy for me
to write a range that satisfies @nogc @safe pure nothrow, etc. This is
because the ranges don't call delegates which are less restrictive,
which opApply does.
I've been thinking about how you would implement opApply so that it
could allow you to run @system code while the iteration itself is @safe,
but then I had another idea. Could we allow foreach to look for a method
(UFCS include) for producing a default range for an object, from a
function named 'range'?
In short this...
foreach(elem; container) {}
Could be transformed into this.
foreach(elem; container.range()) {}
Already works. Just define opSlice for container that returns a range
and then:
foreach(elem; container) {}
is lowered to:
foreach(elem; container[]) {}
--
Dmitry Olshansky
