Rust is an effort by Mozilla Research to develop a language that is as fast and able as C++, but also memory-safe and more expressive.
I've been using it privately for over a year and feel that it is now very much production ready, (there's still a couple of nice-to-have things available only in the nightly releases, but nothing that would prevent you from using the language effectively and the API is very much stable now.)
Rust uses the ownership model in order to check for memory safety violations at compile time.
This means that common bugs, such as use-after-free and dangling-pointers are prevented by the Rust compiler itself, increasing the security and efficiency of your applications by tracking who is responsible for each memory allocation and making it the "owner" responsible for deallocating that memory when no longer needed, thus eliminating the need for a garbage-collector and preserving memory-safety at the same time.
(More at: https://doc.rust-lang.org/stable...)
There's also the concept of borrowing, to allow for a more advanced memory layout, which is explained in detail here: https://doc.rust-lang.org/stable...
Together with lifetimes, which ensure that an object lives as long as it is referenced, (details: https://doc.rust-lang.org/stable...), therefore preventing dangling pointers.
Besides memory-safety, Rust also offers several functional constructs not found in C/C++, such as immutable variables by default, pattern matching, traits, advanced type-inference, concurrency-focused programming and the ability to use Rust as a drop-in-replacement for C/C++, meaning it is possible today to write a Ruby gem or a Python egg in Rust without much trouble.