Add a `write_char` method to `std::fmt::Write`

as accepted in [RFC 526](https://github.com/rust-lang/rfcs/blob/master/text/0526-fmt-text-writer.md).

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index 81710286fde..11d32dbd94a 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -1084,4 +1084,10 @@ impl fmt::Write for String {
         self.push_str(s);
         Ok(())
     }
+
+    #[inline]
+    fn write_char(&mut self, c: char) -> fmt::Result {
+        self.push(c);
+        Ok(())
+    }
 }