chore: remove some uses of * (#569)

src/message/mimebody.rs

@@ -177,20 +177,19 @@ impl MultiPartKind {
     fn to_mime<S: Into<String>>(&self, boundary: Option<S>) -> Mime {
         let boundary = boundary.map_or_else(make_boundary, |s| s.into());
 
-        use self::MultiPartKind::*;
         format!(
             "multipart/{}; boundary=\"{}\"{}",
             match self {
-                Mixed => "mixed",
-                Alternative => "alternative",
-                Related => "related",
-                Encrypted { .. } => "encrypted",
-                Signed { .. } => "signed",
+                Self::Mixed => "mixed",
+                Self::Alternative => "alternative",
+                Self::Related => "related",
+                Self::Encrypted { .. } => "encrypted",
+                Self::Signed { .. } => "signed",
             },
             boundary,
             match self {
-                Encrypted { protocol } => format!("; protocol=\"{}\"", protocol),
-                Signed { protocol, micalg } =>
+                Self::Encrypted { protocol } => format!("; protocol=\"{}\"", protocol),
+                Self::Signed { protocol, micalg } =>
                     format!("; protocol=\"{}\"; micalg=\"{}\"", protocol, micalg),
                 _ => String::new(),
             }
@@ -200,18 +199,17 @@ impl MultiPartKind {
     }
 
     fn from_mime(m: &Mime) -> Option<Self> {
-        use self::MultiPartKind::*;
         match m.subtype().as_ref() {
-            "mixed" => Some(Mixed),
-            "alternative" => Some(Alternative),
-            "related" => Some(Related),
+            "mixed" => Some(Self::Mixed),
+            "alternative" => Some(Self::Alternative),
+            "related" => Some(Self::Related),
             "signed" => m.get_param("protocol").and_then(|p| {
-                m.get_param("micalg").map(|micalg| Signed {
+                m.get_param("micalg").map(|micalg| Self::Signed {
                     protocol: p.as_str().to_owned(),
                     micalg: micalg.as_str().to_owned(),
                 })
             }),
-            "encrypted" => m.get_param("protocol").map(|p| Encrypted {
+            "encrypted" => m.get_param("protocol").map(|p| Self::Encrypted {
                 protocol: p.as_str().to_owned(),
             }),
             _ => None,

src/transport/sendmail/mod.rs

@@ -111,7 +111,7 @@ use async_trait::async_trait;
 use std::marker::PhantomData;
 use std::{
     ffi::OsString,
-    io::prelude::*,
+    io::Write,
     process::{Command, Stdio},
 };