project euler #10: optimization with primes

[bearophile]

Robert Fraser Wrote:
> Yeah that's shorter (vertically; it's almost as long in characters),

This is simpler and faster (runs in 2.19 seconds), and gives the same result, xtakeWhile isn't required because xprimes already stops nicely when the given max N is reached:

import d.func, d.primes, d.string;
void main() {
    putr( sum(xprimes(1_000_000_000)) );
}

Bye,
bearophile