pub trait DefaultContext: Default {
// Required methods
fn default_key() -> &'static str;
fn from_context(context: Context) -> Option<Self>;
fn cast(context: &Context) -> Option<&Self>;
fn cast_mut(context: &mut Context) -> Option<&mut Self>;
fn into_context(self) -> Context;
}Expand description
A well-known context in the Contexts interface.
These contexts have a default key in the contexts map and can be constructed as an empty default value.
Required Methods§
Sourcefn default_key() -> &'static str
fn default_key() -> &'static str
The default key at which this context resides in Contexts.
Sourcefn from_context(context: Context) -> Option<Self>
fn from_context(context: Context) -> Option<Self>
Converts this context type from a generic context type.
Returns Some if the context is of this type. Otherwise, returns None.
Sourcefn cast(context: &Context) -> Option<&Self>
fn cast(context: &Context) -> Option<&Self>
Casts a reference to this context type from a generic context type.
Returns Some if the context is of this type. Otherwise, returns None.
Sourcefn cast_mut(context: &mut Context) -> Option<&mut Self>
fn cast_mut(context: &mut Context) -> Option<&mut Self>
Casts a mutable reference to this context type from a generic context type.
Returns Some if the context is of this type. Otherwise, returns None.
Sourcefn into_context(self) -> Context
fn into_context(self) -> Context
Boxes this context type in the generic context wrapper.
Returns Some if the context is of this type. Otherwise, returns None.
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.