Span::entered method for entering a span and moving it into a guard by value rather than borrowing it (#1252)Thanks to @matklad for contributing to this release!
#[instrument(err)] on functions which return impl Trait (#1236)Thanks to @bkchr and @lfranke for contributing to this release!
#[instrument(err)] on functions with mutable parameters (#1167)#[instrument] with async-trait (#977)syn features ([#928])tracing macros would generate code for events whose levels are disabled statically by the log crate's static_max_level_XXX features (#1175)tracing-futures dependency is no longer required when using #[instrument] on async functions (#808)tracing-attributes minimum dependency to v0.1.12 (#1222)Thanks to @nagisa, @Txuritan, @TaKO8Ki, @okready, and @krojew for contributing to this release!
pin-project-lite dependency to 0.2 (#1108)Span::new, Span::new_root, and Span::new_child_of, which could result in dispatcher::get_default being inlined at the callsite (#994)tracing-core to 0.1.17 (#992)Instrument trait and Instrumented type for attaching a Span to a Future (#808)Copy implementations for Level and LevelFilter (#992)Thanks to @nagisa, and new contributors @SecurityInsanity, @froydnj, @jyn514 and @TaKO8Ki for contributing to this release!
tracing-core to 0.1.15 (#943)tracing-core to fix incorrect calculation of the global max level filter (#908)self in field expressions when instrumenting async-trait functions (#875)Thanks to @anton-dutov, @nightmared, @mystor, and @toshokan for contributing to this release!
LevelFilter::OFF (and thus also the static_max_level_off feature flag) would enable all traces, rather than none (#853)tracing macros and Spans not checking log::max_level before emitting log records (#870)LevelFilter::current) before the per-callsite cache when determining if a span or event is enabled. This significantly improves performance in some use cases (#853)rustc optimizatation of surrounding code (#869, #869)static_max_level_XXX feature flag (#868)LevelFilter is now a re-export of the tracing_core::LevelFilter type, it can now be used interchangably with the versions in tracing-core and tracing-subscriber (#853)LevelFilters and Levels (#853)tracing-core dependency to 0.1.12 (#853)LevelFilter::current() function, which returns the highest level that any subscriber will enable (#853)Subscriber::max_level_hint optional trait method, for setting the value returned by LevelFilter::current() (#853)Thanks to new contributors @cuviper, @ethanboxx, @ben0x539, @dignati, @colelawrence, and @rbtcollins for helping out with this release!
Trace log filter, to guard against log users enabling them by default with blanket level filtering (#833)tracing::field::debug and tracing::field::display functions inside the macros when the “log” feature is enabled (#835)#[instrument] (#672)#[instrument] now emits a compiler warning when ignoring unrecognized input (#672, #786)tracing in async code (#769)tracing-core dependency to 0.1.11log or log-always features are enabled (#753)tracing-core/std feature is enabled but tracing/std is not (#760)Thanks to @nagisa for contributing to this release!
local_inner_macros with $crate:: (#740)Thanks to @bnjjj, @blaenk, and @LukeMathWalker for contributing to this release!
log compatibility feature alongside a tracing Subscriber, log records for spans now include span IDs (#613)#[instrument] on methods that are part of async-trait trait implementations (#711)#[instrument(err)] argument to automatically emit an event if an instrumented function returns Err (#637)#[must_use] attribute to the guard returned by subscriber::set_default (#685)log records emitted by spans much less noisy when span IDs are not available (#613)Thanks to @FintanH, @shepmaster, @inanna-malick, @zekisharif, @bkchr, @majecty, @ilana and @nightmared for contributing to this release!
field::Empty type for declaring empty fields whose values will be recorded later (#548)field::Value implementations for Wrapping and NonZero* numbers (#538)#[instrument] (#569)#[instrument] now emits a helpful compiler error when attempting to skip a function parameter (#600)#[instrument] attribute was placed under an on-by-default feature flag “attributes” (#603)Thanks to @oli-cosmian and @Kobzol for contributing to this release!
Span::with_subscriber method to access the subscriber that tracks a Span (#503)Span::is_none method (#475)LevelFilter::into_level method (#470)LevelFilter::from_level function and From<Level> impl (#471)Span::follows_from that made it impossible to call (#467)log records generated when enabling the log feature flag (#484)#[instrument]ed functions (#397)self parameters when #[instrument]ing methods (#397)skip argument to #[instrument] for excluding function parameters from generated spans (#359)dispatcher::set_default and subscriber::set_default APIs, which return a drop guard (#388)#[instrument]ed async functions not compiling on nightly-2019-09-11 or newer (#342)Subscriber is not in use (#326)log feature will now only cause tracing spans and events to emit log records when a Subscriber is not in use (#346)#[instrument] (#330)log-always feature flag to emit log records even when a Subscriber is set (#346)ansi_term and humantime crates, which were used only for examples (#316)log feature flag is enabled (#304)std::error::Error as a new primitive type (#277)format_args messages without curly braces as delimiters (#288)tracing-core dependency to 0.1.5 (#294)tracing-attributes dependency to 0.1.2 (#297)no-std + liballoc (#263)#[instrument] attribute on async fns no longer requires a feature flag (#258)#[instrument] macro now works on generic functions (#262)#[instrument] attribute for automatically adding spans to functions (#253)log feature flag is enabled (#180).tracing-core minimum dependency version to 0.1.2 (#174).tracing-core APIs (#174).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).tracing:: (#152).cfg_if dependency to 0.1.9.log feature is enabled (#131).