# Crubit `rs_std` library

This directory contains the `rs_std` C++ library that provides the following
APIs:
- Manually authored APIs that help work with Rust builtin types.  For
  example, `rs_std::rs_char` represents Rust's `char` type (a separate type from
  C++'s `char32_t` is needed to detect certain invalid bit patterns that result
  in Undefined Behavior in Rust;  additionally `char32_t` takes at least 32
  bits, rather than exactly 32 bits).
- (Not yet implemented) Automatically generated C++ bindings for Rust standard
  library.