Consider this code, which is used as an example only:
auto scaleAll(int[] xs, int m) {
return xs.map!(x => m * x);
}
As m is captured, the delegate for map will rightly allocate the
closure in the GC heap.
In C++, you would write the lambda to capture m by value, but
this is not a facility in D.
I can write scaleAll like this:
auto scaleAll(int[] xs, int m) @nogc {
return repeat(m).zip(xs).map!(mx => mx[0] * mx[1]);
}
So that repeat(m) stores m, but it is quite hacky to work like
this.
I could write my own range that does this, but this is also not
desirable.
Are there any established patterns, libraries, or language
features that can help avoid the GC allocation in a principled
way here?
