The historical answer is that originally Felix programs were being written for the Shootout and the compiler was upgraded so it performed well. In fact it trashed everything. Then control of the Shootout changed hands and Felix got dropped by the new manager. Today, there are no forums for developing new languages.
Felix "targets" people that would like to use Haskell or Ocaml but have a ton of code in C and C++ to interface with. Felix is a C++ upgrade: it discard the syntax, but retains ABI compatibility, at quite some cost to things like safety for example.
Felix is more or less guaranteed to perform on par with C/C++ or better for the simple reason you can embed C++ directly into Felix, this works because Felix generates C++. And of course you can link to your favourite libraries with minimal syntax.
type mytype = "My::Type";
ctor mytype : int = "My::Type ($1)";
fun addup : mytype * mytype -> mytype = "$1.addup($2)";
Unlike Ocaml which requires a lot of hard to write glue logic, Felix and C++ share types and functions. Typically only type glue is required to create a bridge.
There's no such thing as safe code. So to do as you suggest requires some set of suitable concepts of relative safety, together with some way to enforce them. I am very interested in implementing mechanisms that provide guarantees. And not just safety. Another would be licence management (e.g allow only BSD licenced code to be used) .. that's a legal safety guarantee :)
Rust and Felix both try to be general languages so they're both targeting that. Felix has a better type system. Rust provides more secure but restricted protocol for concurrency, Felix has no such restrictions, it's specifically designed to support shared memory concurrency, which Rust specifically doesn't allow. Rust uses message passing but organises via the memory management mechanism to do it very fast.
Felix "targets" people that would like to use Haskell or Ocaml but have a ton of code in C and C++ to interface with. Felix is a C++ upgrade: it discard the syntax, but retains ABI compatibility, at quite some cost to things like safety for example.
Felix is more or less guaranteed to perform on par with C/C++ or better for the simple reason you can embed C++ directly into Felix, this works because Felix generates C++. And of course you can link to your favourite libraries with minimal syntax.
Unlike Ocaml which requires a lot of hard to write glue logic, Felix and C++ share types and functions. Typically only type glue is required to create a bridge.