Remove must_use call from ensure! and bail! expansions

Author: dtolnay

src/ensure.rs

@@ -818,17 +818,17 @@ macro_rules! __fallback_ensure {
     };
     ($cond:expr, $msg:literal $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($msg));
+            return $crate::private::Err($crate::__anyhow!($msg));
         }
     };
     ($cond:expr, $err:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($err));
+            return $crate::private::Err($crate::__anyhow!($err));
         }
     };
     ($cond:expr, $fmt:expr, $($arg:tt)*) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($fmt, $($arg)*));
+            return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*));
         }
     };
 }

src/macros.rs

@@ -54,13 +54,13 @@
 #[macro_export]
 macro_rules! bail {
     ($msg:literal $(,)?) => {
-        return $crate::private::Err($crate::anyhow!($msg))
+        return $crate::private::Err($crate::__anyhow!($msg))
     };
     ($err:expr $(,)?) => {
-        return $crate::private::Err($crate::anyhow!($err))
+        return $crate::private::Err($crate::__anyhow!($err))
     };
     ($fmt:expr, $($arg:tt)*) => {
-        return $crate::private::Err($crate::anyhow!($fmt, $($arg)*))
+        return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*))
     };
 }
 
@@ -75,13 +75,13 @@ macro_rules! bail {
         return $crate::private::Err($crate::Error::msg("pattern does not contain `{}`"))
     };
     ($msg:literal $(,)?) => {
-        return $crate::private::Err($crate::anyhow!($msg))
+        return $crate::private::Err($crate::__anyhow!($msg))
     };
     ($err:expr $(,)?) => {
-        return $crate::private::Err($crate::anyhow!($err))
+        return $crate::private::Err($crate::__anyhow!($err))
     };
     ($fmt:expr, $($arg:tt)*) => {
-        return $crate::private::Err($crate::anyhow!($fmt, $($arg)*))
+        return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*))
     };
 }
 
@@ -145,17 +145,17 @@ macro_rules! ensure {
     };
     ($cond:expr, $msg:literal $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($msg));
+            return $crate::private::Err($crate::__anyhow!($msg));
         }
     };
     ($cond:expr, $err:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($err));
+            return $crate::private::Err($crate::__anyhow!($err));
         }
     };
     ($cond:expr, $fmt:expr, $($arg:tt)*) => {
         if !$cond {
-            return $crate::private::Err($crate::anyhow!($fmt, $($arg)*));
+            return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*));
         }
     };
 }
@@ -225,3 +225,25 @@ macro_rules! anyhow {
         $crate::Error::msg($crate::private::format!($fmt, $($arg)*))
     };
 }
+
+// Not public API. This is used in the implementation of some of the other
+// macros, in which the must_use call is not needed because the value is known
+// to be used.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __anyhow {
+    ($msg:literal $(,)?) => ({
+        let error = $crate::private::format_err($crate::private::format_args!($msg));
+        error
+    });
+    ($err:expr $(,)?) => ({
+        use $crate::private::kind::*;
+        let error = match $err {
+            error => (&error).anyhow_kind().new(error),
+        };
+        error
+    });
+    ($fmt:expr, $($arg:tt)*) => {
+        $crate::Error::msg($crate::private::format!($fmt, $($arg)*))
+    };
+}