From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 12 Jul 2020 12:03:08 +0000 (+0100)
Subject: error_from_losedetails
X-Git-Tag: otter-0.2.0~1363
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=e88fed53daf57320afc9ddb1a2e86b9e3ae73df2;p=otter.git

error_from_losedetails
---

diff --git a/src/error.rs b/src/error.rs
index e52953b5..7d443193 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -88,3 +88,13 @@ macro_rules! display_as_debug {
   }
 }
 pub use crate::display_as_debug;
+
+#[macro_export]
+macro_rules! error_from_losedetails {
+  {$to:ty, $variant:ident, $from:ty} => {
+    impl From<$from> for $to {
+      fn from(_: $from) -> Self { <$to>::$variant }
+    }
+  }
+}
+pub use crate::error_from_losedetails;
diff --git a/src/pieces.rs b/src/pieces.rs
index 17e2acc2..42db5809 100644
--- a/src/pieces.rs
+++ b/src/pieces.rs
@@ -23,9 +23,7 @@ pub enum SVGProcessError {
   WriteFail,
 }
 display_as_debug!{SVGProcessError}
-impl From<fmt::Error> for SVGProcessError {
-  fn from(_: fmt::Error) -> Self { SVGProcessError::WriteFail }
-}
+error_from_losedetails!{SVGProcessError, WriteFail, fmt::Error}
 
 #[throws(SVGProcessError)]
 pub fn svg_rescale_path(input: &str, scale: f64) -> String {