From 15628891efac1cd55f86588ca3814df59e2af122 Mon Sep 17 00:00:00 2001
From: Kornel <kornel@geekhood.net>
Date: Mon, 19 Aug 2019 10:24:47 +0100
Subject: [PATCH] Require buf reference to implement Write, not buf itself

Allows one level of indirection less
---
 src/template.rs       |  2 +-
 src/template_utils.rs | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/template.rs b/src/template.rs
index c7b72f8..60d4933 100644
--- a/src/template.rs
+++ b/src/template.rs
@@ -41,7 +41,7 @@ impl Template {
         writeln!(
             out,
             "\n\
-             pub fn {name}<W: Write>(mut out: W{args}) -> io::Result<()> {{\n\
+             pub fn {name}<W>(mut out: &mut W{args}) -> io::Result<()> where W: ?Sized, for<'a> &'a mut W: Write {{\n\
              {body}\
              Ok(())\n\
              }}",
diff --git a/src/template_utils.rs b/src/template_utils.rs
index 35ef9c0..0fa01f2 100644
--- a/src/template_utils.rs
+++ b/src/template_utils.rs
@@ -6,7 +6,7 @@
 /// formats the value using Display and then html-encodes the result.
 pub trait ToHtml {
     /// Write self to `out`, which is in html representation.
-    fn to_html<W: Write + ?Sized>(&self, out: &mut W) -> io::Result<()>;
+    fn to_html<W>(&self, out: &mut W) -> io::Result<()> where W: ?Sized, for<'a> &'a mut W: Write;
 }
 
 /// Wrapper object for data that should be outputted as raw html
@@ -16,21 +16,21 @@ pub struct Html<T>(pub T);
 
 impl<T: Display> ToHtml for Html<T> {
     #[inline]
-    fn to_html<W: Write + ?Sized>(&self, out: &mut W) -> io::Result<()> {
+    fn to_html<W>(&self, mut out: &mut W) -> io::Result<()>  where W: ?Sized, for<'a> &'a mut W: Write {
         write!(out, "{}", self.0)
     }
 }
 
 impl<T: Display> ToHtml for T {
     #[inline]
-    fn to_html<W: Write + ?Sized>(&self, out: &mut W) -> io::Result<()> {
+    fn to_html<W>(&self, out: &mut W) -> io::Result<()>  where W: ?Sized, for<'a> &'a mut W: Write {
         write!(ToHtmlEscapingWriter(out), "{}", self)
     }
 }
 
-struct ToHtmlEscapingWriter<'a, W: Write + ?Sized>(&'a mut W);
+struct ToHtmlEscapingWriter<'w, W: ?Sized>(&'w mut W);
 
-impl<'a, W: Write + ?Sized> Write for ToHtmlEscapingWriter<'a, W> {
+impl<'w, W> Write for ToHtmlEscapingWriter<'w, W> where W: ?Sized, for<'a> &'a mut W: Write {
     #[inline]
     // This takes advantage of the fact that `write` doesn't have to write everything,
     // and the call will be retried with the rest of the data
@@ -56,10 +56,10 @@ impl<'a, W: Write + ?Sized> Write for ToHtmlEscapingWriter<'a, W> {
     }
 }
 
-impl<'a, W: Write + ?Sized> ToHtmlEscapingWriter<'a, W> {
+impl<'w, W> ToHtmlEscapingWriter<'w, W> where W: ?Sized, for<'a> &'a mut W: Write {
     #[inline(never)]
     fn write_one_byte_escaped(
-        out: &mut W,
+        mut out: &mut W,
         data: &[u8],
     ) -> io::Result<usize> {
         let next = data.get(0);