# 0.1.16 (July 8, 2020)
### Added
- **attributes**: Support for arbitrary expressions as fields in `#[instrument]` (#672)
- **attributes**: `#[instrument]` now emits a compiler warning when ignoring unrecognized
input (#672, #786)
- Improved documentation on using `tracing` in async code (#769)
### Changed
- Updated `tracing-core` dependency to 0.1.11
### Fixed
- **macros**: Excessive monomorphization in macros, which could lead to
longer compilation times (#787)
- **log**: Compiler warnings in macros when `log` or `log-always` features
are enabled (#753)
- Compiler error when `tracing-core/std` feature is enabled but `tracing/std` is
not (#760)
Thanks to @nagisa for contributing to this release!
# 0.1.15 (June 2, 2020)
### Changed
- **macros**: Replaced use of legacy `local_inner_macros` with `$crate::` (#740)
### Added
- Docs fixes and improvements (#742, #731, #730)
Thanks to @bnjjj, @blaenk, and @LukeMathWalker for contributing to this release!
# 0.1.14 (May 14, 2020)
### Added
- **log**: When using the [`log`] compatibility feature alongside a `tracing`
`Subscriber`, log records for spans now include span IDs (#613)
- **attributes**: Support for using `#[instrument]` on methods that are part of
[`async-trait`] trait implementations (#711)
- **attributes**: Optional `#[instrument(err)]` argument to automatically emit
an event if an instrumented function returns `Err` (#637)
- Added `#[must_use]` attribute to the guard returned by
`subscriber::set_default` (#685)
### Changed
- **log**: Made [`log`] records emitted by spans much less noisy when span IDs are
not available (#613)
### Fixed
- Several typos in the documentation (#656, #710, #715)
Thanks to @FintanH, @shepmaster, @inanna-malick, @zekisharif, @bkchr, @majecty,
@ilana and @nightmared for contributing to this release!
[`async-trait`]: https://crates.io/crates/async-trait
[`log`]: https://crates.io/crates/log
# 0.1.13 (February 26, 2019)
### Added
- **field**: `field::Empty` type for declaring empty fields whose values will be
recorded later (#548)
- **field**: `field::Value` implementations for `Wrapping` and `NonZero*`
numbers (#538)
- **attributes**: Support for adding arbitrary literal fields to spans generated
by `#[instrument]` (#569)
- **attributes**: `#[instrument]` now emits a helpful compiler error when
attempting to skip a function parameter (#600)
### Changed
- **attributes**: The `#[instrument]` attribute was placed under an on-by-default
feature flag "attributes" (#603)
### Fixed
- Broken and unresolvable links in RustDoc (#595)
Thanks to @oli-cosmian and @Kobzol for contributing to this release!
# 0.1.12 (January 11, 2019)
### Added
- `Span::with_subscriber` method to access the subscriber that tracks a `Span`
(#503)
- API documentation now shows which features are required by feature-flagged
items (#523)
- Improved README examples (#496)
- Documentation links to related crates (#507)
# 0.1.11 (December 20, 2019)
### Added
- `Span::is_none` method (#475)
- `LevelFilter::into_level` method (#470)
- `LevelFilter::from_level` function and `From<Level>` impl (#471)
- Documented minimum supported Rust version (#482)
### Fixed
- Incorrect parameter type to `Span::follows_from` that made it impossible to
call (#467)
- Missing whitespace in `log` records generated when enabling the `log` feature
flag (#484)
- Typos and missing links in documentation (#405, #423, #439)
# 0.1.10 (October 23, 2019)
### Added
- Support for destructuring in arguments to `#[instrument]`ed functions (#397)
- Generated field for `self` parameters when `#[instrument]`ing methods (#397)
- Optional `skip` argument to `#[instrument]` for excluding function parameters
from generated spans (#359)
- Added `dispatcher::set_default` and `subscriber::set_default` APIs, which
return a drop guard (#388)
### Fixed
- Some minor documentation errors (#356, #370)
# 0.1.9 (September 13, 2019)
### Fixed
- Fixed `#[instrument]`ed async functions not compiling on `nightly-2019-09-11`
or newer (#342)
### Changed
- Significantly reduced performance impact of skipped spans and events when a
`Subscriber` is not in use (#326)
- The `log` feature will now only cause `tracing` spans and events to emit log
records when a `Subscriber` is not in use (#346)
### Added
- Added support for overriding the name of the span generated by `#[instrument]`
(#330)
- `log-always` feature flag to emit log records even when a `Subscriber` is set
(#346)
# 0.1.8 (September 3, 2019)
### Changed
- Reorganized and improved API documentation (#317)
### Removed
- Dev-dependencies on `ansi_term` and `humantime` crates, which were used only
for examples (#316)
# 0.1.7 (August 30, 2019)
### Changed
- New (curly-brace free) event message syntax to place the message in the first
field rather than the last (#309)
### Fixed
- Fixed a regression causing macro stack exhaustion when the `log` feature flag
is enabled (#304)
# 0.1.6 (August 20, 2019)
### Added
- `std::error::Error` as a new primitive type (#277)
- Support for mixing key-value fields and `format_args` messages without curly
braces as delimiters (#288)
### Changed
- `tracing-core` dependency to 0.1.5 (#294)
- `tracing-attributes` dependency to 0.1.2 (#297)
# 0.1.5 (August 9, 2019)
### Added
- Support for `no-std` + `liballoc` (#263)
### Changed
- Using the `#[instrument]` attribute on `async fn`s no longer requires a
feature flag (#258)
### Fixed
- The `#[instrument]` macro now works on generic functions (#262)
# 0.1.4 (August 8, 2019)
### Added
- `#[instrument]` attribute for automatically adding spans to functions (#253)
# 0.1.3 (July 11, 2019)
### Added
- Log messages when a subscriber indicates that a span has closed, when the
`log` feature flag is enabled (#180).
### Changed
- `tracing-core` minimum dependency version to 0.1.2 (#174).
### Fixed
- Fixed an issue where event macro invocations with a single field, using local
variable shorthand, would recur infinitely (#166).
- Fixed uses of deprecated `tracing-core` APIs (#174).
# 0.1.2 (July 6, 2019)
### Added
- `Span::none()` constructor, which does not require metadata and
returns a completely empty span (#147).
- `Span::current()` function, returning the current span if it is
known to the subscriber (#148).
### Fixed
- Broken macro imports when used prefixed with `tracing::` (#152).
# 0.1.1 (July 3, 2019)
### Changed
- `cfg_if` dependency to 0.1.9.
### Fixed
- Compilation errors when the `log` feature is enabled (#131).
- Unclear wording and typos in documentation (#124, #128, #142).
# 0.1.0 (June 27, 2019)
- Initial release