Add: Interoperable (#74).

Sources/CoreKit/Interoperable+Yield.swift

@@ -0,0 +1,37 @@
+//=----------------------------------------------------------------------------=
+// This source file is part of the Ultimathnum open source project.
+//
+// Copyright (c)  2023 Oscar Byström Ericsson
+// Licensed under Apache License, Version 2.0
+//
+// See http://www.apache.org/licenses/LICENSE-2.0 for license information.
+//=----------------------------------------------------------------------------=
+
+//*============================================================================*
+// MARK: * Interoperable x Yield
+//*============================================================================*
+
+extension Interoperable {
+
+    //=------------------------------------------------------------------------=
+    // MARK: Transformations
+    //=------------------------------------------------------------------------=
+
+    /// Yields its `stdlib` representation.
+    ///
+    /// - Note: Use the `stdlib()` method to transfer ownership.
+    ///
+    @inlinable public var stdlib: Stdlib {
+        mutating _read {
+            let stdlib = self.stdlib()
+            yield stdlib
+            self = Self(stdlib)
+        }
+
+        mutating _modify {
+            var stdlib = self.stdlib()
+            yield &stdlib
+            self = Self(stdlib)
+        }
+    }
+}

Sources/CoreKit/Interoperable.swift

@@ -0,0 +1,29 @@
+//=----------------------------------------------------------------------------=
+// This source file is part of the Ultimathnum open source project.
+//
+// Copyright (c)  2023 Oscar Byström Ericsson
+// Licensed under Apache License, Version 2.0
+//
+// See http://www.apache.org/licenses/LICENSE-2.0 for license information.
+//=----------------------------------------------------------------------------=
+
+//*============================================================================*
+// MARK: * Interoperable
+//*============================================================================*
+
+/// A type with a standard-library-compatible representation.
+public protocol Interoperable {
+
+    /// The standard-library-compatible representation of `Self`.
+    associatedtype Stdlib
+
+    //=------------------------------------------------------------------------=
+    // MARK: Initializers
+    //=------------------------------------------------------------------------=
+
+    /// Reinterprets the given `source` as this type.
+    @inlinable init(_ source: consuming Stdlib)
+
+    /// Reiinterprets `self` as a standard-library-compatible type.
+    @inlinable consuming func stdlib() -> Stdlib
+}