On 3/25/14, 12:16 PM, Dicebot wrote:
On Monday, 24 March 2014 at 22:26:10 UTC, Joseph Rushton Wakeling wrote:
On 24/03/14 14:20, Dicebot wrote:
I think there is one design mistake with current InputRange rules
that makes
usage so inconsistent. We have `empty` but don't have any distinct
`not yet
started` state. If calling `popFront` at least once was required before
accessing `front`, I can't imagine the case where having any
non-trivial code in
`front` would have been necessary.
I floated some ideas along those lines, for a "first" method that
would be automatically called immediately before the first call to
front, popFront, etc., whatever came first.
I was thinking about something more simple. Current pattern is:
while (!r.empty)
{
auto useme = r.front;
r.popFront;
}
And I think this would have been more practical:
r.popFront;
while (!r.empty)
{
// same
}
So every range is supposed to start in "init" state and provide data
only after first popFront. No other changes. It is not a silver bullet
but looks like an improvement over current design to me.
Suggestion: focusing on what to do within the present context is more
productive.
Andrei
