From 785b3952b9916c332df5026b462ad75b4ae159d4 Mon Sep 17 00:00:00 2001
From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com>
Date: Sun, 23 Oct 2022 22:30:08 +0200
Subject: [PATCH] cfg_match

---
 Cargo.lock       |  2 +-
 Cargo.toml       |  2 +-
 src/cfg_match.rs | 58 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 4e1a577..6c3634b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3,5 +3,5 @@
 version = 3
 
 [[package]]
-name = "haha"
+name = "uwu"
 version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 9ea908b..64cbcf9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "haha"
+name = "uwu"
 version = "0.1.0"
 edition = "2021"
 
diff --git a/src/cfg_match.rs b/src/cfg_match.rs
index e69de29..5703544 100644
--- a/src/cfg_match.rs
+++ b/src/cfg_match.rs
@@ -0,0 +1,58 @@
+#[macro_export]
+macro_rules! cfg_match {
+    () => {};
+    (_ => { $($tt:tt)* }) => {
+        $($tt)*
+    };
+    (
+        $head_pattern:meta => { $($head_body:tt)* }
+        $($rest:tt)*
+    ) => {
+
+        #[cfg($head_pattern)]
+        $crate::cfg_match! { _ => { $($head_body)* } }
+
+        #[cfg(not($head_pattern))]
+        $crate::cfg_match! {
+            $($rest)*
+        }
+    };
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn correct_one_selected() {
+        crate::cfg_match! {
+            any() => {
+                panic!();
+            }
+            all() => {
+
+            }
+            any() => {
+                panic!();
+            }
+        }
+    }
+
+    #[test]
+    fn underscore() {
+        crate::cfg_match! {
+            _ => {}
+        }
+    }
+
+    #[test]
+    fn fallback() {
+        crate::cfg_match! {
+            any() => {
+                panic!();
+            }
+            any() => {
+                panic!();
+            }
+            _ => {}
+        }
+    }
+}