1 files changed, 56 insertions, 2 deletions
diff --git a/src/ptr.rs b/src/ptr.rs
index 082edf2..08c3788 100644
--- a/src/ptr.rs
+++ b/src/ptr.rs
@@ -3,11 +3,65 @@
 //! Smart pointer type aliases.
 use std::rc::Rc;
 
-/// A smart pointer unique to the holder.
+use paste::paste;
+
+use crate::errors::ptr::SomePtrError;
+
+/// A smart pointer for a interface in the transient scope.
 pub type TransientPtr<Interface> = Box<Interface>;
 
-/// A smart pointer to a shared resource.
+/// A smart pointer to a interface in the singleton scope.
 pub type SingletonPtr<Interface> = Rc<Interface>;
 
 /// A smart pointer to a factory.
 pub type FactoryPtr<FactoryInterface> = Rc<FactoryInterface>;
+
+/// Some smart pointer.
+#[derive(strum_macros::IntoStaticStr)]
+pub enum SomePtr<Interface>
+where
+    Interface: 'static + ?Sized,
+{
+    /// A smart pointer to a interface in the transient scope.
+    Transient(TransientPtr<Interface>),
+
+    /// A smart pointer to a interface in the singleton scope.
+    Singleton(SingletonPtr<Interface>),
+
+    /// A smart pointer to a factory.
+    Factory(FactoryPtr<Interface>),
+}
+
+macro_rules! create_as_variant_fn {
+    ($variant: ident) => {
+        paste! {
+            #[doc =
+                "Returns as " [<$variant:lower>] ".\n"
+                "\n"
+                "# Errors\n"
+                "Will return Err if it's not a " [<$variant:lower>] "."
+            ]
+            pub fn [<$variant:lower>](self) -> Result<[<$variant Ptr>]<Interface>, SomePtrError>
+            {
+                if let SomePtr::$variant(ptr) = self {
+                    return Ok(ptr);
+                }
+
+
+                Err(SomePtrError::WrongPtrType {
+                    expected: stringify!($variant),
+                    found: self.into()
+                })
+            }
+        }
+    };
+}
+
+impl<Interface> SomePtr<Interface>
+where
+    Interface: 'static + ?Sized,
+{
+    create_as_variant_fn!(Transient);
+    create_as_variant_fn!(Singleton);
+    create_as_variant_fn!(Factory);
+}