Peter Alexander:
I'm not a fan of introducing new keywords or introducing
breaking changes in D code (even though I don't use Case3). I
think this might just be something we have to live with,
Using a custom property is maybe acceptable (this @copy doesn't
need to be a built-in, probably it's not too much hard to define
it with user-defined attributes):
void main() {
auto data = [0, 1, 2, 3];
foreach (@copy x; data)
x++;
}
But there are other solutions, like asking D tool (like D IDEs or
future D lints) to show a warning here.
Another solution is to require an already present keyword ("new"
means it's a copy, it's not related to heap allocations) for the
Case3:
void main() {
auto data = [0, 1, 2, 3];
foreach (new x; data)
x++;
}
Bye,
bearophile
