Attribute Macro entity_ptr_id 

#[entity_ptr_id]

Syntax:

#[entity_ptr_id(WrapperName)] -- default policy (256)
#[entity_ptr_id(WrapperName, options...)] -- custom policy (named argument)
#[entity_ptr_id(WrapperName, opaque)] -- opaque ID with default policy (256)
#[entity_ptr_id(WrapperName, options..., opaque)] -- opaque ID with custom policy
pub struct|enum|union ObjType { ... }

Options:

• policy = <PolicyType>: specify allocation policy type, e.g., Policy256, 512, etc.
• opaque: makes the wrapper opaque (restricts field visibility to crate-only)
• allocator_type = AllocTypeName: generates a type alias for the corresponding EntityAlloc<..., ...>

Generates:

/// non-opaque wrapper
pub struct $WrapperName(pub $ObjType);

/// opaque wrapper
pub struct $WrapperName(pub(crate) $ObjType);

impl $crate::IEntityAllocPtr for $WrapperName {
    type ObjectT = $ObjType;
    type PolicyT = $PolicyType;
    type AllocT = $crate::EntityAlloc<$ObjType, Self::PolicyT>;

    fn from_raw_ptrid(ptr: PtrID<Self::ObjectT, Self::PolicyT>) -> Self {
        Self(ptr)
    }
    fn into_raw_ptrid(self) -> PtrID<Self::ObjectT, Self::PolicyT> {
        self.0
    }
}