From 16df977e1820e1004376903b6f6196d5969bce4e Mon Sep 17 00:00:00 2001
From: "Neal H. Walfield" <neal@pep.foundation>
Date: Tue, 26 Mar 2019 10:20:24 +0100
Subject: openpgp: Move destructures_to macro to macros.rs

---
 openpgp/src/macros.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'openpgp/src/macros.rs')

diff --git a/openpgp/src/macros.rs b/openpgp/src/macros.rs
index 20aaa6e5..50be3afa 100644
--- a/openpgp/src/macros.rs
+++ b/openpgp/src/macros.rs
@@ -1,5 +1,25 @@
 use std::cmp;
 
+// Turns an `if let` into an expression so that it is possible to do
+// things like:
+//
+// ```rust,nocompile
+// if destructures_to(Foo::Bar(_) = value)
+//    || destructures_to(Foo::Bam(_) = value) { ... }
+// ```
+macro_rules! destructures_to {
+    ( $error: pat = $expr:expr ) => {
+        {
+            let x = $expr;
+            if let $error = x {
+                true
+            } else {
+                false
+            }
+        }
+    };
+}
+
 macro_rules! trace {
     ( $TRACE:expr, $fmt:expr, $($pargs:expr),* ) => {
         if $TRACE {
-- 
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