Macro impl_derived_property 

macro_rules! impl_derived_property {
    (
        $name:ident,
        $entity:ident,
        [$($dependency:ident),*]
        $(, [$($global_dependency:ident),*])?,
        |$($param:ident),+| $derive_fn:expr
        $(, $($extra:tt)+)*
    ) => { ... };
    (
        @construct_compute_fn
        $entity:ident,
        [$($dependency:ident),*],
        [$($global_dependency:ident),*],
        |$($param:ident),+| $derive_fn:expr
    ) => { ... };
    (@unwrap_or $value:expr, $_default:expr) => { ... };
    (@unwrap_or, $default:expr) => { ... };
    (
        @with_option_display_default
        $name:ident,
        $entity:ident,
        [$($dependency:ident),*],
        [$($global_dependency:ident),*],
        |$($param:ident),+| $derive_fn:expr
        $(, default_const = $default_const:expr)?
        $(, display_impl = $display_impl:expr)?
        $(, canonical_value = $canonical_value:ty)?
        $(, make_canonical = $make_canonical:expr)?
        $(, make_uncanonical = $make_uncanonical:expr)?
        $(, index_id_fn = $index_id_fn:expr)?
        $(, collect_deps_fn = $collect_deps_fn:expr)?
        $(, ctor_registration = $ctor_registration:expr)?
    ) => { ... };
}

Implements the Property trait for an existing type as a derived property.

Accepts the same parameters as define_derived_property!, except the first parameter is the name of a type assumed to already be declared rather than a type declaration. This is the derived property equivalent of impl_property!. It calls impl_property! with the appropriate derived property parameters.