pub struct Metadata<'a> { /* private fields */ }
Expand description
Metadata about a log message.
Use
Metadata
structs are created when users of the library use
logging macros.
They are consumed by implementations of the Log
trait in the
enabled
method.
Record
s use Metadata
to determine the log message’s severity
and target.
Users should use the log_enabled!
macro in their code to avoid
constructing expensive log messages.
Examples
ⓘ
use log::{Record, Level, Metadata};
struct MyLogger;
impl log::Log for MyLogger {
fn enabled(&self, metadata: &Metadata) -> bool {
metadata.level() <= Level::Info
}
fn log(&self, record: &Record) {
if self.enabled(record.metadata()) {
println!("{} - {}", record.level(), record.args());
}
}
fn flush(&self) {}
}
Implementations
Trait Implementations
sourceimpl<'a> Hash for Metadata<'a>
impl<'a> Hash for Metadata<'a>
sourcefn hash<__H: Hasher>(&self, state: &mut __H)
fn hash<__H: Hasher>(&self, state: &mut __H)
Feeds this value into the given [
Hasher
]. Read more1.3.0fn hash_slice<H>(data: &[Self], state: &mut H)where
H: Hasher,
fn hash_slice<H>(data: &[Self], state: &mut H)where
H: Hasher,
Feeds a slice of this type into the given [
Hasher
]. Read moresourceimpl<'a> Ord for Metadata<'a>
impl<'a> Ord for Metadata<'a>
sourceimpl<'a> PartialEq<Metadata<'a>> for Metadata<'a>
impl<'a> PartialEq<Metadata<'a>> for Metadata<'a>
sourceimpl<'a> PartialOrd<Metadata<'a>> for Metadata<'a>
impl<'a> PartialOrd<Metadata<'a>> for Metadata<'a>
sourcefn partial_cmp(&self, other: &Metadata<'a>) -> Option<Ordering>
fn partial_cmp(&self, other: &Metadata<'a>) -> Option<Ordering>
1.0.0const fn lt(&self, other: &Rhs) -> bool
const fn lt(&self, other: &Rhs) -> bool
1.0.0const fn le(&self, other: &Rhs) -> bool
const fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for
self
and other
) and is used by the <=
operator. Read more1.0.0const fn gt(&self, other: &Rhs) -> bool
const fn gt(&self, other: &Rhs) -> bool
impl<'a> Eq for Metadata<'a>
impl<'a> StructuralEq for Metadata<'a>
impl<'a> StructuralPartialEq for Metadata<'a>
Auto Trait Implementations
impl<'a> RefUnwindSafe for Metadata<'a>
impl<'a> Send for Metadata<'a>
impl<'a> Sync for Metadata<'a>
impl<'a> Unpin for Metadata<'a>
impl<'a> UnwindSafe for Metadata<'a>
Blanket Implementations
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstablefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> ToOwned for Twhere
T: Clone,
impl<T> ToOwned for Twhere
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
fn clone_into(&self, target: &mut T)
fn clone_into(&self, target: &mut T)
Uses borrowed data to replace owned data, usually by cloning. Read more