mirror of
https://github.com/bitcoin/bitcoin.git
synced 2026-01-20 07:09:15 +01:00
d5c8199b79
faa23738fcrefactor: Enable clang-tidy bugprone-unused-return-value (MarcoFalke)fa114be27bAdd util::Expected (std::expected) (MarcoFalke) Pull request description: Some low-level code could benefit from being able to use `std::expected` from C++23: * Currently, some code is using `std::optional<E>` to denote an optional error. This is fine, but a bit confusing, because `std::optional` is normally used for values, not errors. Using `std::expected<void, E>` is clearer. * Currently, some code is using `std::variant<V, E>` to denote either a value or an error. This is fine, but a bit verbose, because `std::variant` requires a visitor or get_if/holds_alternative instead of a simple call of the `operator bool` for `std::expected`. In theory, `util::Result` could be taught to behave similar to `std::expected` (see https://github.com/bitcoin/bitcoin/pull/34005). However, it is unclear if this is the right approach: * `util::Result` is mostly meant for higher level code, where errors come with translated error messages. * `std::expected` is mostly meant for lower level code, where errors could be an enum, or any other type. * https://github.com/bitcoin/bitcoin/pull/25665 aims to minimize the memory footprint of the error by wrapping it in a unique_ptr internally. `std::expected` requires the value and error to be "nested within it" (https://cplusplus.github.io/LWG/issue4141). So from a memory-layout perspective, the two are not compatible. * `std::expected` also comes with `std::unexpected`, which also does not map cleanly to `util::Result`. So just add a minimal drop-in port of `std::expected`. ACKs for top commit: romanz: tACKfaa23738fcsedited: Re-ACKfaa23738fchodlinator: ACKfaa23738fcrkrux: light Code Review ACKfaa23738fcryanofsky: Code review ACKfaa23738fc, only adding `value_or` implementation and `CheckedReturnTypes` clang-tidy commit since last review. stickies-v: ACKfaa23738fcTree-SHA512: fdbd0f6bf439738ffe6a68da5522f1051537f8df9c308eb90bef6bd2e06931d79f1c5da22d5500765e9cb1d801d5be39e11e10d47c9659fec1a8c8804cb7c872