Type Alias tracing_subscriber::fmt::writer::OptionalWriter
source · pub type OptionalWriter<T> = EitherWriter<T, Sink>;
Expand description
A writer which may or may not be enabled.
This may be used by MakeWriter
implementations that wish to
conditionally enable or disable the returned writer based on a span or
event’s Metadata
.
Aliased Type§
enum OptionalWriter<T> {
A(T),
B(Sink),
}
Variants§
Implementations§
source§impl<T> OptionalWriter<T>
impl<T> OptionalWriter<T>
sourcepub fn none() -> Self
pub fn none() -> Self
Returns a disabled writer.
Any bytes written to the returned writer are discarded.
This is equivalent to returning Option::None
.
sourcepub fn some(t: T) -> Self
pub fn some(t: T) -> Self
Returns an enabled writer of type T
.
This is equivalent to returning Option::Some
.
Trait Implementations§
source§impl<T> From<Option<T>> for OptionalWriter<T>
impl<T> From<Option<T>> for OptionalWriter<T>
source§impl<A: PartialEq, B: PartialEq> PartialEq for EitherWriter<A, B>
impl<A: PartialEq, B: PartialEq> PartialEq for EitherWriter<A, B>
source§fn eq(&self, other: &EitherWriter<A, B>) -> bool
fn eq(&self, other: &EitherWriter<A, B>) -> bool
This method tests for
self
and other
values to be equal, and is used
by ==
.source§impl<A, B> Write for EitherWriter<A, B>
impl<A, B> Write for EitherWriter<A, B>
source§fn write(&mut self, buf: &[u8]) -> Result<usize>
fn write(&mut self, buf: &[u8]) -> Result<usize>
Write a buffer into this writer, returning how many bytes were written. Read more
source§fn flush(&mut self) -> Result<()>
fn flush(&mut self) -> Result<()>
Flush this output stream, ensuring that all intermediately buffered
contents reach their destination. Read more
source§fn write_all(&mut self, buf: &[u8]) -> Result<()>
fn write_all(&mut self, buf: &[u8]) -> Result<()>
Attempts to write an entire buffer into this writer. Read more
source§fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()>
fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()>
Writes a formatted string into this writer, returning any error
encountered. Read more
source§fn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
🔬This is a nightly-only experimental API. (
can_vector
#69941)