Macro declare_capability 

macro_rules! declare_capability {
    ($name:ident: $($T:ty),+) => { ... };
}

Declare a named struct that implements the given capability traits.

Unlike create_capability!, this macro creates a named type that can be used as a generic parameter (e.g., in component static macros). Use this when you need to name the capability type, such as when passing it to a component’s static buffer macro.

Usage Example

declare_capability!(MyCapability: ProcessManagementCapability);

let manager = components::manager::ManagerComponent::new(
    board_kernel,
    mux_alarm,
    MyCapability,
)
.finalize(components::manager_component_static!(
    AlarmHw,
    MyCapability,
));

Difference from create_capability!()

declare_capability!() creates a named type, whereas create_capability! does not. If possible, use create_capability!. However, for components that need the capability struct named in the static constructor macro, use declare_capability!() to create the named struct that is used in the macro expansion and in the component finalize() method.

Supporting Multiple Capabilities

Some type signatures require multiple capabilities. This macro supports declaring multiple capabilities. For example:

kernel::declare_capability!(ProcessConsoleCap:
    kernel::capabilities::ProcessManagementCapability,
    kernel::capabilities::ProcessStartCapability
);

Restrictions

This helper macro cannot be called from #![forbid(unsafe_code)] crates, and is used by trusted code to generate a capability type.

Safety

This macro can only be used in a context that is allowed to use unsafe. Specifically, an internal allow(unsafe_code) directive will conflict with any forbid(unsafe_code) at the crate or block level.