Trait tracing::field::AsField [−][src]
Trait implemented to allow a type to be used as a field key.
ⓘNote
Note: Although this is implemented for both theField
type and any type that can be borrowed as an&str
, onlyField
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
fn as_field(&self, metadata: &Metadata<'_>) -> Option<Field>
[src]
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
.