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History

merge-script 95a78058d9 Merge rust-bitcoin/rust-bitcoin#3182 : Refactor Rust version checking `ad34a98c61` Refactor Rust version checking (Martin Habovstiak) `7d5ce89dad` Fix type ambiguity in IO tests (Martin Habovstiak) Pull request description: Conditional compilation depending on Rust version using `cfg` had the disadvantage that we had to write the same code multiple times, compile it multiple times, execute it multiple times, update it multiple times... Apart from obvious maintenance issues the build script wasn't generating the list of allowed `cfg`s so those had to be maintained manually in `Cargo.toml`. This was fixable by printing an appropriate line but it's best to do it together with the other changes. Because we cannot export `cfg` flags from a crate to different crates we take a completely different approach: we define a macro called `rust_version` that takes a very naturally looking condition such as `if >= 1.70 {}`. This macro is auto-generated so that it produces different results based on the compiler version - it either expands to first block or the second block (after `else`). This way, the other crates can simply call the macro when needed. Unfortunately some minimal maintenance is still needed: to update the max version number when a newer version is used. (Note that code will still work with higher versions, it only limits which conditions can be used in downstream code.) This can be automated with the pin update script or we could just put the pin file into the `internals` directory and read the value from there. Not automating isn't terrible either since anyone adding a cfg with higher version will see a nice error about unknown version of Rust and can update it manually. Because this changes syntax to a more naturally looking version number, as a side effect the `cond_const` macro could be also updated to use the new macro under the hood, providing much nicer experience - it is no longer needed to provide human-readable version of the version string to put in the note about `const`ness requiring a newer version. As such the note is now always there using a single source of truth. It's also a great moment to introduce this change right now since there's currently no conditional compilation used in `bitcoin` crate making the changes minimal. However it is not yet added to `bitcoin-io` since `bitcoin-io` is not depending on `internals`. It might be a reason to start depending on it but that's for later discussion. ACKs for top commit: apoelstra: ACK `ad34a98c61` successfully ran local tests tcharding: ACK `ad34a98c61` Tree-SHA512: 7a82017fc51ba1b473ca638c7bdbf5c893da0a78c70ea8f1a0241049e7874592fad328abd60b3e09a00439b771e7cfc5ebad5e874314d15a48271ec6cb2d7bb7		2024-08-20 00:18:27 +00:00
..
contrib	CI: Remove shebang from non-executable scripts	2024-05-31 10:10:00 +10:00
src	Merge rust-bitcoin/rust-bitcoin#3182 : Refactor Rust version checking	2024-08-20 00:18:27 +00:00
CHANGELOG.md	io: Bump version to 0.1.2	2024-03-15 06:25:55 +11:00
Cargo.toml	Refactor Rust version checking	2024-08-19 15:21:01 +02:00
README.md	chore: format and standardize all markdowns files	2024-04-27 06:29:23 -03:00

README.md

Rust-Bitcoin IO Library

The std::io module is not exposed in no-std Rust so building no-std applications which require reading and writing objects via standard traits is not generally possible. Thus, this library exists to export a minimal version of std::io's traits which we use in rust-bitcoin so that we can support no-std applications.

These traits are not one-for-one drop-ins, but are as close as possible while still implementing std::io's traits without unnecessary complexity.