On Wednesday, 16 October 2013 at 20:33:23 UTC, H. S. Teoh wrote:
I'm of the view that code should only require the minimum of
assumptions
it needs to actually work. If your code can work with mutable
types,
then let it take a mutable (unqualified) type. If your code
works
without modifying input data, then let it take const. Only if
your code
absolutely will not work correctly unless the data is
guaranteed to
never change, ever, by anyone, should it take immutable.
Sounds reasonable. Which one of the following would you prefer?
foo1(const T t) {
takes_immutable(t.idup);
}
foo2(immutable(T) t) {
takes_immutable(t);
}
I'd say foo2, which puts the burden of the copy on the caller.
However, if the caller already has an immutable value an
unecessary copy is avoided.
