tracing::field

Trait AsField

Source
pub trait AsField: Sealed {
    // Required method
    fn as_field(&self, metadata: &Metadata<'_>) -> Option<Field>;
}
Expand description

Trait implemented to allow a type to be used as a field key.

Note: Although this is implemented for both the
Field type and any
type that can be borrowed as an &str, only Field
allows O(1) access.
Indexing a field with a string results in an iterative search that performs
string comparisons. Thus, if possible, once the key for a field is known, it
should be used whenever possible.

Required Methods§

Source

fn as_field(&self, metadata: &Metadata<'_>) -> Option<Field>

Attempts to convert &self into a Field with the specified metadata.

If metadata defines this field, then the field is returned. Otherwise, this returns None.

Implementations on Foreign Types§

Source§

impl AsField for str

Source§

fn as_field(&self, metadata: &Metadata<'_>) -> Option<Field>

Implementors§

Source§

impl AsField for Field

Source§

impl<'a> AsField for &'a Field