On Thursday, 26 December 2013 at 23:52:09 UTC, Adam D. Ruppe
wrote:
On Thursday, 26 December 2013 at 23:23:02 UTC, Gordon wrote:
But the "b" in "main" retains its original value of 42.
Try printing the b in main again AFTER printing c. You should
see the change.
std.algorithm for the most part doesn't actually do any of its
calculations until it has to. This allows it to save speed
skipping work it doesn't need, and make it possible to map
infinite series and stuff like that.
So the line c = map....; just prepares the calculation, it
doesn't actually run the function. The writeln(c) forces
evaluation. You can also force evaluation immediately by
calling .array on the thing, which calculates it and puts the
result in a new array.
Thanks!
