#[repr(u32)]
pub enum ViewState {
    New,
    NotNew,
}
Expand description

Indicates if this data instance has been seen (viewed).

For each instance (identified by the key), the middleware internally maintains a view_state relative to each DataReader. The view_state can either be NEW or NOT_NEW.

The view_state available in the SampleInfo is a snapshot of the view_state of the instance relative to the DataReader used to access the samples at the time the collection was obtained (i.e., at the time read or take was called). The view_state is therefore the same for all samples in the returned collection that refer to the same instance. Once an instance has been detected as not having any “live” writers and all the samples associated with the instance are ‘taken’ from the DataReader, the middleware can reclaim all local resources regarding the instance. Future samples will be treated as ‘never seen’.

Cf. SampleState

See DDS spec v.14 Section 2.2.2.5.1.8 Interpretation of the SampleInfo view_state

Variants

New

indicates that either this is the first time that the DataReader has ever accessed samples of that instance, or else that the DataReader has accessed previous samples of the instance, but the instance has since been reborn (i.e., become not-alive and then alive again).

NotNew

indicates that the DataReader has already accessed samples of the same instance and that the instance has not been reborn since

Implementations

Set that contains all possible states

Trait Implementations

The resulting type after applying the & operator.

Performs the & operation. Read more

Create a BitFlags with no flags set (in other words, with a value of 0). Read more

Create a BitFlags with all flags set. Read more

The resulting type after applying the | operator.

Performs the | operation. Read more

The resulting type after applying the ^ operator.

Performs the ^ operation. Read more

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

The resulting type after applying the ! operator.

Performs the unary ! operation. Read more

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

This method tests for !=.

The underlying integer type.

A value with no bits set.

The value used by the Default implementation. Equivalent to EMPTY, unless customized. Read more

A value with all flag bits set.

A slice that contains each variant exactly one.

The name of the type for debug formatting purposes. Read more

Return the bits as a number type.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

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

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.