Apparently, the parent post is now too old to edit, so I'll post a correction here. In light of helpful input, I was wrong about the following:
1) Tail call optimizations are fine, the documentation is just a bit ambiguous on the matter.
2) Explicit vectorization is available in nightly.
3) The equivalent of -ffast-math is technically available, though very inconvenient to use. There may be workarounds, I'm not sure.
These points, coupled with the ability to do performant threading (in theory, even with the syntax I'd prefer), go a long way to alleviating some of my performance concerns. Well written (nightly) Rust may be closer to C++ in numerical performance than I initially thought. I'd like for some of these things to be much more convenient to use than they are currently, but the opportunities are there.
1) Tail call optimizations are fine, the documentation is just a bit ambiguous on the matter.
2) Explicit vectorization is available in nightly.
3) The equivalent of -ffast-math is technically available, though very inconvenient to use. There may be workarounds, I'm not sure.
These points, coupled with the ability to do performant threading (in theory, even with the syntax I'd prefer), go a long way to alleviating some of my performance concerns. Well written (nightly) Rust may be closer to C++ in numerical performance than I initially thought. I'd like for some of these things to be much more convenient to use than they are currently, but the opportunities are there.