Struct tracing_subscriber::fmt::writer::BoxMakeWriter
source · [−]pub struct BoxMakeWriter { /* private fields */ }
Expand description
A writer that erases the specific io::Write
and MakeWriter
types being used.
This is useful in cases where the concrete type of the writer cannot be known until runtime.
Examples
A function that returns a Subscriber
that will write to either stdout or stderr:
fn dynamic_writer(use_stderr: bool) -> impl Subscriber {
let writer = if use_stderr {
BoxMakeWriter::new(std::io::stderr)
} else {
BoxMakeWriter::new(std::io::stdout)
};
tracing_subscriber::fmt().with_writer(writer).finish()
}
Implementations
sourceimpl BoxMakeWriter
impl BoxMakeWriter
sourcepub fn new<M>(make_writer: M) -> Self where
M: for<'a> MakeWriter<'a> + Send + Sync + 'static,
pub fn new<M>(make_writer: M) -> Self where
M: for<'a> MakeWriter<'a> + Send + Sync + 'static,
Constructs a BoxMakeWriter
wrapping a type implementing MakeWriter
.
Trait Implementations
sourceimpl Debug for BoxMakeWriter
impl Debug for BoxMakeWriter
sourceimpl<'a> MakeWriter<'a> for BoxMakeWriter
impl<'a> MakeWriter<'a> for BoxMakeWriter
type Writer = Box<dyn Write + 'a>
type Writer = Box<dyn Write + 'a>
The concrete io::Write
implementation returned by make_writer
. Read more
sourcefn make_writer(&'a self) -> Self::Writer
fn make_writer(&'a self) -> Self::Writer
Auto Trait Implementations
impl !RefUnwindSafe for BoxMakeWriter
impl Send for BoxMakeWriter
impl Sync for BoxMakeWriter
impl Unpin for BoxMakeWriter
impl !UnwindSafe for BoxMakeWriter
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<'a, M> MakeWriterExt<'a> for M where
M: MakeWriter<'a>,
impl<'a, M> MakeWriterExt<'a> for M where
M: MakeWriter<'a>,
sourcefn with_max_level(self, level: Level) -> WithMaxLevel<Self> where
Self: Sized,
fn with_max_level(self, level: Level) -> WithMaxLevel<Self> where
Self: Sized,
Wraps self
and returns a MakeWriter
that will only write output
for events at or below the provided verbosity Level
. For instance,
Level::TRACE
is considered to be _more verbosethan
Level::INFO`. Read more
sourcefn with_min_level(self, level: Level) -> WithMinLevel<Self> where
Self: Sized,
fn with_min_level(self, level: Level) -> WithMinLevel<Self> where
Self: Sized,
Wraps self
and returns a MakeWriter
that will only write output
for events at or above the provided verbosity Level
. Read more
sourcefn with_filter<F>(self, filter: F) -> WithFilter<Self, F> where
Self: Sized,
F: Fn(&Metadata<'_>) -> bool,
fn with_filter<F>(self, filter: F) -> WithFilter<Self, F> where
Self: Sized,
F: Fn(&Metadata<'_>) -> bool,
Wraps self
with a predicate that takes a span or event’s Metadata
and returns a bool
. The returned MakeWriter
’s
MakeWriter::make_writer_for
method will check the predicate to
determine if a writer should be produced for a given span or event. Read more
sourcefn and<B>(self, other: B) -> Tee<Self, B>ⓘNotable traits for Tee<A, B>impl<A, B> Write for Tee<A, B> where
A: Write,
B: Write,
where
Self: Sized,
B: MakeWriter<'a> + Sized,
fn and<B>(self, other: B) -> Tee<Self, B>ⓘNotable traits for Tee<A, B>impl<A, B> Write for Tee<A, B> where
A: Write,
B: Write,
where
Self: Sized,
B: MakeWriter<'a> + Sized,
A: Write,
B: Write,
Combines self
with another type implementing MakeWriter
, returning
a new MakeWriter
that produces writers that write to both
outputs. Read more
sourcefn or_else<W, B>(self, other: B) -> OrElse<Self, B> where
Self: MakeWriter<'a, Writer = OptionalWriter<W>> + Sized,
B: MakeWriter<'a> + Sized,
W: Write,
fn or_else<W, B>(self, other: B) -> OrElse<Self, B> where
Self: MakeWriter<'a, Writer = OptionalWriter<W>> + Sized,
B: MakeWriter<'a> + Sized,
W: Write,
Combines self
with another type implementing MakeWriter
, returning
a new MakeWriter
that calls other
’s make_writer
if self
’s
make_writer
returns OptionalWriter::none
. Read more