Struct log::Metadata

[+] Show declaration

pub struct Metadata<'a> { /* fields omitted */ }

[−] 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.

Records 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

impl<'a> Metadata<'a>[−]

pub fn builder() -> MetadataBuilder<'a>[−]

Returns a new builder.

pub fn level(&self) -> Level[−]

The verbosity level of the message.

pub fn target(&self) -> &'a str[−]

The name of the target of the directive.

Trait Implementations

impl<'a> Clone for Metadata<'a>[+]

[+] Show hidden undocumented items

fn clone(&self) -> Metadata<'a>[−]

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl<'a> Debug for Metadata<'a>[+]

[+] Show hidden undocumented items

fn fmt(&self, f: &mut Formatter<'_>) -> Result[−]

Formats the value using the given formatter.

impl<'a> Eq for Metadata<'a>

impl<'a> Hash for Metadata<'a>[+]

[+] Show hidden undocumented items

fn hash<__H: Hasher>(&self, state: &mut __H)[−]

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, [−]

Feeds a slice of this type into the given [Hasher].

impl<'a> Ord for Metadata<'a>[+]

[+] Show hidden undocumented items

fn cmp(&self, other: &Metadata<'a>) -> Ordering[−]

This method returns an [Ordering] between self and other.

[+] Expand attributes

#[must_use]fn max(self, other: Self) -> Self[−]

Compares and returns the maximum of two values.

[+] Expand attributes

#[must_use]fn min(self, other: Self) -> Self[−]

Compares and returns the minimum of two values.

[+] Expand attributes

#[must_use]fn clamp(self, min: Self, max: Self) -> Self[−]

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<'a> PartialEq<Metadata<'a>> for Metadata<'a>[+]

[+] Show hidden undocumented items

fn eq(&self, other: &Metadata<'a>) -> bool[−]

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Metadata<'a>) -> bool[−]

This method tests for !=.

impl<'a> PartialOrd<Metadata<'a>> for Metadata<'a>[+]

[+] Show hidden undocumented items

fn partial_cmp(&self, other: &Metadata<'a>) -> Option<Ordering>[−]

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Metadata<'a>) -> bool[−]

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Metadata<'a>) -> bool[−]

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Metadata<'a>) -> bool[−]

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Metadata<'a>) -> bool[−]

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> StructuralEq for Metadata<'a>

impl<'a> StructuralPartialEq for Metadata<'a>