I had a discussion recently about the proper use of "save" when
passing to foreach or algorithms, as well as read the thread
about algorithms being hard to use. It was concluded this the
problem mostly came from:
a) Lack of proper testing.
b) Missing or inaccurate input type checking.
I decided to donate some of my time to investigate and improve on
both these points.
Here is what I found:
*"Save" issues:
*"minPos". Atsolutly no backup is ever made, and this method will
return an empty range ALL the time.
*"fill(Range1, Range2)". Save occurs only once, but not within
loop body. An out of range exception occurs should Range1.length
> 2* Range2.length.
*"No specifier" issues:
*The following algorithms do not validate the type of their
ranges:
**"minPos": Should be "isInputRange".
**"skipOver": Should be "isInputRange".
*"isForwardRange" could be "isInputRange" issues:
**"countUntil".
Also, the functions:
*"fill(Range, Value)"
*"uninitializedFill(Range, Value)"
*"fill(Range1, Range2)"
*"initializeAll(Range)"
*"moveAll(Range1, Range2)"
*"moveSome(Range1, Range2)"
*"swapFront(R1, R2)"
For some reason, the output ranges (Range/Range2/R2) for all the
above functions are defined as needing "isInputRange", when it
should really be "isOutputRange" (or Forward range for
uninitializedFill/initializeAll ?)
Finally: "fill(Range1, Range2)" requires "Range1" to be a forward
range, so that it can be repeated. However, if Range1
hasInfinity, then only isInputRange is needed.
----
I did not go much more in depth, but I think it may be a good
starting point? I apologize if I gave any false positives. Would
this be something I should fix myself?
----
Something else I noticed it that even the most basic algorithms
seem to go out of their way to avoid using "foreach". For
example, "count", "equal", "minCount", "minPos". etc. Doing this
potentially short-circuits any call to opApply if that range
defines it.
