Hands down the best thing about C++ for me is that with modern C++ you can write relatively safe clean code while taking advantage of decades of robust libraries.
Yeah, Rust is a big step forward in some respects, but it'll be almost a decade before we see it catch up to C++'s incredible ecosystem. C++ is almost the lingua franca of finance, for instance.
Rust can already take advantage of the C ecosystem quite easily. Rust/C++ usability is a major goal for 2017. I'm hoping that by year end you can have the best of both worlds. The advantages of Rust for new code and the mountain of code that exists for C and for C++.
Well, the C ecosystem has always been easy. The nice thing about C is that generating bindings is a breeze.
I've never been a fan of bindings to C++ libraries. They usually always feel cumbersome and hardly idiomatic. Like it or not, the best way forward is to bite the bullet and slowly natively reimplement the libraries we need in Rust.
I'm starting some work next year on writing some of the basic libraries that someone in the electronic trading world might want to start writing applications in Rust (a FIX/FAST engine and a port of the Aeron message transport). I'm already also writing a native Rust port of our internal consolidated market data library. We already have a Go port along with the C++ code and plan on open sourcing these pretty soon. This stuff tends to be highly proprietary and slow to develop so hopefully we can get some of the more cutting edge users to pitch in and get more people using the language.
C++ FFI will likely be difficult given that unlike C, C++ lacks a stable ABI since the standard doesn't define an ABI, and leaves it up to compilers to implement.
Yeah, Rust is a big step forward in some respects, but it'll be almost a decade before we see it catch up to C++'s incredible ecosystem. C++ is almost the lingua franca of finance, for instance.