Rust-like std for C++

A C++ 20 module of Rust-like std.

C++’s language features are exciting, but I’m tired of the std.
Made this for coding with C++ easier.

I believe a standalone static-library std can solve many C++ pain points.
It doesn't have to mirror another language's stdlib — it could be designed to fit C++ idioms better.
My time is limited, so I anchored the design on Rust's std.

Require

• clang 18+
• gcc 15+
• windows(clang 22+ with msvc std header)

limitation

Linear Type

C++ has no linear type support, so types like NotNull and Unique cannot be fully enforced.
This project keeps them as part of the API and provides memcpy-like checks for null state.

Choice(match)

No good design for a general Choice interface yet. Option/Result are implemented independently for now and may migrate once a Choice API is designed.

Auto Trait

Could perhaps be done with some C++20 reflection magic, but I plan to wait for C++26.

Progress

Module	Area	Types & APIs
core	types	Option<T>, Result<T,E>
	traits	Impl / dyn dispatch, Clone, Copy, From / Into / AsRef / AsMut, PartialEq (partial)
	fmt	Display, Debug, Formatter, format_string, Arguments
	ptr	NonNull<T>(just api, no linear type support), ref<T>, mut_ref<T>, dyn<Trait>
	mem	ManuallyDrop, MaybeUninit
	str	str, CStr
	num	NonZero, integer traits
	sync	Atomic<T>, memory ordering
	ops	FnOnce, FnMut, Fn
	misc	Hash / Hasher, Duration, panic / PanicInfo, slice (partial)
alloc	containers	Box<T>, Vec<T>, String, CString
	shared ownership	Rc<T> / Weak<T>, Arc<T> / Weak<T>
	allocator	Layout, Global, alloc / dealloc
std	io	Read, Write, Seek, BufRead traits, BufReader / BufWriter, Cursor<T>, Stdin / Stdout / Stderr, io::Error, print / println / eprint / eprintln
	thread	spawn, sleep, park, yield_now, JoinHandle<T>, Builder, ThreadId
	sync	Mutex<T> / MutexGuard, mpsc::channel / sync_channel
	process	Command, Child, ExitStatus, Stdio, Output, ChildStdin / ChildStdout / ChildStderr (impl Read/Write), abort, exit, id
	env	var, set_var, remove_var
	time	Instant, SystemTime, Duration
runtime	defaults	default allocator (operator new), panic handler (rstd_panic_impl)

Not yet implemented

• iter: Iterator / IntoIterator
• collections: HashMap, BTreeMap
• fs: Path, File, read / write / metadata
• net: TcpStream, TcpListener, UdpSocket
• sync: RwLock, Condvar, Barrier, Once
• async: Future, async / await
• os: OsString / OsStr
• error: Error trait (defined, not widely used)

Documents

work in progress

Installation

FetchContent_Declare(
  rstd
  GIT_REPOSITORY https://github.com/hypengw/rstd.git
  GIT_TAG master
  # GIT_TAG <commit>
  EXCLUDE_FROM_ALL)
FetchContent_MakeAvailable(rstd)

Related

Type Systems for Memory Safety
Borrowing Trouble: The Difficulties Of A C++ Borrow-Checker
rust-to-cpp-implementing-the-question-mark-operator rusty-cpp: Bringing Rust's safety to C++
fragile: A polyglot compiler that supports Rust, C++, Go
cxx: Safe interop between Rust and C++