Enum Select 

pub enum Select {
    Always,
    OnUse(&'static [&'static str]),
    OnRequest,
    OnConfig {
        key: &'static str,
        any_of: &'static [&'static str],
        default: &'static str,
    },
}

When a link that picks its capabilities carries this one.

A plain build carries every capability in its graph; this is read by a link that replays a kit for one app (lumenc package --static), after the app’s own [capabilities] table, which names a capability to keep or drop outright.

Variants

Always

Every app.

OnUse(&'static [&'static str])

An app whose sources mention any of these: a builtin’s name, a config key. The scan errs toward yes, the same way CapabilityEnv::sources_mention does.

OnRequest

Only an app that asks for it by name. For a subsystem that exists for development rather than for the app’s users.

OnConfig

An app whose lumen.toml sets key to one of any_of. key is a dotted path, section.field; default stands in for it when the file leaves it unset. For one of several interchangeable implementations an app picks between in its configuration.

Fields

key: &'static str

Dotted path of the key, for example render.backend.

any_of: &'static [&'static str]

The values that select this capability.

default: &'static str

The value an absent key reads as.

Trait Implementations

impl Clone for Select

fn clone(&self) -> Select

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Select

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

Formats the value using the given formatter.

impl PartialEq for Select

fn eq(&self, other: &Select) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Select

impl Eq for Select

impl StructuralPartialEq for Select