The Rust Core Library

The Rust Core Library is the dependency-free foundation of The Rust Standard Library. It is the portable glue between the language and its libraries, defining the intrinsic and primitive building blocks of all Rust code. It links to no upstream libraries, no system libraries, and no libc.

The core library is minimal: it isn't even aware of heap allocation, nor does it provide concurrency or I/O. These things require platform integration, and this library is platform-agnostic.

It is not recommended to use the core library. The stable functionality of libcore is reexported from the standard library. The composition of this library is subject to change over time; only the interface exposed through libstd is intended to be stable.

How to use the core library

This library is built on the assumption of a few existing symbols:

• memcpy, memcmp, memset - These are core memory routines which are often generated by LLVM. Additionally, this library can make explicit calls to these functions. Their signatures are the same as found in C. These functions are often provided by the system libc, but can also be provided by librlibc which is distributed with the standard rust distribution.

• rust_begin_unwind - This function takes three arguments, a fmt::Arguments, a &str, and a uint. These three arguments dictate the panic message, the file at which panic was invoked, and the line. It is up to consumers of this core library to define this panic function; it is only required to never return.