rustc-ap-serialize 308.0.0

Automatically published version of the package `serialize` in the rust-lang/rust repository from commit b7da2c6e12a6b2a2343e2f1e66fe4f6a1ad55463 The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish

Support code for encoding and decoding types.