Starting new subxt crate; configs implemented

new/src/utils/yesnomaybe.rs

@@ -0,0 +1,82 @@
+// Copyright 2019-2025 Parity Technologies (UK) Ltd.
+// This file is dual-licensed as Apache-2.0 or GPL-3.0.
+// see LICENSE for license details.
+
+/// A unit marker enum.
+pub enum Yes {}
+/// A unit marker enum.
+pub enum Maybe {}
+/// A unit marker enum.
+pub enum No {}
+
+/// This is implemented for [`Yes`] and [`No`] and
+/// allows us to check at runtime which of these types is present.
+pub trait YesNo {
+    /// [`Yes`]
+    fn is_yes() -> bool {
+        false
+    }
+    /// [`No`]
+    fn is_no() -> bool {
+        false
+    }
+}
+
+impl YesNo for Yes {
+    fn is_yes() -> bool {
+        true
+    }
+}
+impl YesNo for No {
+    fn is_no() -> bool {
+        true
+    }
+}
+
+/// This is implemented for [`Yes`] and [`Maybe`] and
+/// allows us to check at runtime which of these types is present.
+pub trait YesMaybe {
+    /// [`Yes`]
+    fn is_yes() -> bool {
+        false
+    }
+    /// [`Maybe`]
+    fn is_maybe() -> bool {
+        false
+    }
+}
+
+impl YesMaybe for Yes {
+    fn is_yes() -> bool {
+        true
+    }
+}
+impl YesMaybe for Maybe {
+    fn is_maybe() -> bool {
+        true
+    }
+}
+
+/// This is implemented for [`No`] and [`Maybe`] and
+/// allows us to check at runtime which of these types is present.
+pub trait NoMaybe {
+    /// [`No`]
+    fn is_no() -> bool {
+        false
+    }
+    /// [`Maybe`]
+    fn is_maybe() -> bool {
+        false
+    }
+}
+
+impl NoMaybe for No {
+    fn is_no() -> bool {
+        true
+    }
+}
+impl NoMaybe for Maybe {
+    fn is_maybe() -> bool {
+        true
+    }
+}