yes, i'm looking forward eagerly to rust, especially because it has algebraic datatypes and pattern matching. not sure how it will stack up to D speedwise, though.
What in particular are you not sure about in terms of performance? With the exception of segmented stacks, Rust adheres to the zero-cost principle just as C++ does.
not any expensive-looking features per se, simply that from looking at new languages, especially the ones with powerful features, speed is the hardest and usually the last thing to be achieved. i think ats is the only exception i've seen to that.
