refactor

- no need to force Strings into BStrings. We actually prefer String if
  we know it's valid UTF-8.
- Let's avoid exposing anything from the `time` crate directly. Instead
  consider adding support for a format string.

git-date/src/time/write.rs

@@ -2,27 +2,14 @@ use crate::time::Sign;
 use crate::Time;
 use bstr::BString;
 use time::format_description::well_known::Iso8601;
-use time::formatting::Formattable;
 
+/// Serialization with standard `git` format
 impl Time {
-    /// Serialize this instance into a Iso8601 BString.
+    /// Serialize this instance into memory, similar to what [`write_to()`][Self::write_to()] would do with arbitrary `Write` implementations.
     pub fn to_bstring(&self) -> BString {
-        time::OffsetDateTime::from_unix_timestamp(self.seconds_since_unix_epoch as i64)
-            .expect("always valid unix time")
-            .replace_offset(time::UtcOffset::from_whole_seconds(self.offset_in_seconds).expect("valid offset"))
-            .format(&Iso8601::DEFAULT)
-            .unwrap()
-            .into()
-    }
-
-    /// Serialize this instance into a BString, formatting it using the provided `time::format_description`
-    pub fn to_bstring_with_formatter(&self, formatter: &(impl Formattable + ?Sized)) -> BString {
-        time::OffsetDateTime::from_unix_timestamp(self.seconds_since_unix_epoch as i64)
-            .expect("always valid unix time")
-            .replace_offset(time::UtcOffset::from_whole_seconds(self.offset_in_seconds).expect("valid offset"))
-            .format(formatter)
-            .unwrap()
-            .into()
+        let mut buf = Vec::with_capacity(64);
+        self.write_to(&mut buf).expect("write to memory cannot fail");
+        buf.into()
     }
 
     /// Serialize this instance to `out` in a format suitable for use in header fields of serialized git commits or tags.
@@ -81,3 +68,15 @@ impl Time {
         }) + 2 /*space + sign*/ + 2 /*hours*/ + 2 /*minutes*/
     }
 }
+
+/// Formatting
+impl Time {
+    /// Format this instance as Iso8601 string.
+    pub fn to_iso_8601(&self) -> String {
+        time::OffsetDateTime::from_unix_timestamp(self.seconds_since_unix_epoch as i64)
+            .expect("always valid unix time")
+            .replace_offset(time::UtcOffset::from_whole_seconds(self.offset_in_seconds).expect("valid offset"))
+            .format(&Iso8601::DEFAULT)
+            .expect("well-known format into memory never fails")
+    }
+}

git-repository/src/revision/spec/parse/error.rs

@@ -38,7 +38,7 @@ impl std::fmt::Display for CandidateInfo {
             CandidateInfo::FindError { source } => write!(f, "lookup error: {}", source),
             CandidateInfo::Tag { name } => write!(f, "tag {:?}", name),
             CandidateInfo::Object { kind } => std::fmt::Display::fmt(kind, f),
-            CandidateInfo::Commit { date, title } => write!(f, "commit {} {:?}", date.to_bstring(), title),
+            CandidateInfo::Commit { date, title } => write!(f, "commit {} {:?}", date.to_iso_8601(), title),
         }
     }
 }