Monomorphize all functions

This commit monomorphizes all functions, turning functions like:

```rust
fn foo<T: Into<Bar>>(baz: T) {
    baz = baz.into();

    // function here
}
```

Into functions like:

```rust
fn foo<T: Into<Bar>>(baz: T) {
    _foo(baz.into())
}

fn _foo(baz: Bar) {
    // function here
}
```

This avoids binary bloat and improves build times, by reducing the amount of
code duplication.

11 files changed, 279 insertions, 56 deletions

diff --git a/src/model/channel/channel_id.rs b/src/model/channel/channel_id.rs
index f939be8..e3034f7 100644
--- a/src/model/channel/channel_id.rs
+++ b/src/model/channel/channel_id.rs
@@ -88,7 +88,15 @@ impl ChannelId {
     #[inline]
     pub fn create_reaction<M, R>(&self, message_id: M, reaction_type: R) -> Result<()>
         where M: Into<MessageId>, R: Into<ReactionType> {
-        http::create_reaction(self.0, message_id.into().0, &reaction_type.into())
+        self._create_reaction(message_id.into(), &reaction_type.into())
+    }
+
+    fn _create_reaction(
+        &self,
+        message_id: MessageId,
+        reaction_type: &ReactionType,
+    ) -> Result<()> {
+        http::create_reaction(self.0, message_id.0, reaction_type)
     }
 
     /// Deletes this channel, returning the channel on a successful deletion.
@@ -107,7 +115,11 @@ impl ChannelId {
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
     #[inline]
     pub fn delete_message<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        http::delete_message(self.0, message_id.into().0)
+        self._delete_message(message_id.into())
+    }
+
+    fn _delete_message(&self, message_id: MessageId) -> Result<()> {
+        http::delete_message(self.0, message_id.0)
     }
 
     /// Deletes all messages by Ids from the given vector in the given channel.
@@ -133,6 +145,11 @@ impl ChannelId {
             .into_iter()
             .map(|message_id| message_id.as_ref().0)
             .collect::<Vec<u64>>();
+
+        self._delete_messages(ids)
+    }
+
+    fn _delete_messages(&self, ids: Vec<u64>) -> Result<()> {
         let len = ids.len();
 
         if len == 0 || len > 100 {
@@ -168,17 +185,31 @@ impl ChannelId {
     ///
     /// [`Reaction`]: struct.Reaction.html
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
+    #[inline]
     pub fn delete_reaction<M, R>(&self,
                                  message_id: M,
                                  user_id: Option<UserId>,
                                  reaction_type: R)
                                  -> Result<()>
         where M: Into<MessageId>, R: Into<ReactionType> {
+        self._delete_reaction(
+            message_id.into(),
+            user_id.into(),
+            &reaction_type.into(),
+        )
+    }
+
+    fn _delete_reaction(
+        &self,
+        message_id: MessageId,
+        user_id: Option<UserId>,
+        reaction_type: &ReactionType,
+    ) -> Result<()> {
         http::delete_reaction(
             self.0,
-            message_id.into().0,
+            message_id.0,
             user_id.map(|uid| uid.0),
-            &reaction_type.into(),
+            reaction_type,
         )
     }
 
@@ -229,8 +260,14 @@ impl ChannelId {
     /// [`Message`]: struct.Message.html
     /// [`the limit`]: ../builder/struct.EditMessage.html#method.content
     #[cfg(feature = "utils")]
+    #[inline]
     pub fn edit_message<F, M>(&self, message_id: M, f: F) -> Result<Message>
         where F: FnOnce(EditMessage) -> EditMessage, M: Into<MessageId> {
+        self._edit_message(message_id.into(), f)
+    }
+
+    fn _edit_message<F>(&self, message_id: MessageId, f: F) -> Result<Message>
+        where F: FnOnce(EditMessage) -> EditMessage {
         let msg = f(EditMessage::default());
 
         if let Some(content) = msg.0.get(&"content") {
@@ -243,7 +280,7 @@ impl ChannelId {
 
         let map = utils::vecmap_to_json_map(msg.0);
 
-        http::edit_message(self.0, message_id.into().0, &Value::Object(map))
+        http::edit_message(self.0, message_id.0, &Value::Object(map))
     }
 
     /// Search the cache for the channel with the Id.
@@ -277,7 +314,11 @@ impl ChannelId {
     /// [Read Message History]: permissions/constant.READ_MESSAGE_HISTORY.html
     #[inline]
     pub fn message<M: Into<MessageId>>(&self, message_id: M) -> Result<Message> {
-        http::get_message(self.0, message_id.into().0)
+        self._message(message_id.into())
+    }
+
+    fn _message(&self, message_id: MessageId) -> Result<Message> {
+        http::get_message(self.0, message_id.0)
             .map(|mut msg| {
                 msg.transform_content();
 
@@ -350,7 +391,11 @@ impl ChannelId {
     /// [`Message`]: struct.Message.html
     #[inline]
     pub fn pin<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        http::pin_message(self.0, message_id.into().0)
+        self._pin(message_id.into())
+    }
+
+    fn _pin(&self, message_id: MessageId) -> Result<()> {
+        http::pin_message(self.0, message_id.0)
     }
 
     /// Gets the list of [`Message`]s which are pinned to the channel.
@@ -379,14 +424,29 @@ impl ChannelId {
     ) -> Result<Vec<User>> where M: Into<MessageId>,
                                  R: Into<ReactionType>,
                                  U: Into<Option<UserId>> {
+        self._reaction_users(
+            message_id.into(),
+            &reaction_type.into(),
+            limit,
+            after.into(),
+        )
+    }
+
+    fn _reaction_users(
+        &self,
+        message_id: MessageId,
+        reaction_type: &ReactionType,
+        limit: Option<u8>,
+        after: Option<UserId>,
+    ) -> Result<Vec<User>> {
         let limit = limit.map_or(50, |x| if x > 100 { 100 } else { x });
 
         http::get_reaction_users(
             self.0,
-            message_id.into().0,
-            &reaction_type.into(),
+            message_id.0,
+            reaction_type,
             limit,
-            after.into().map(|x| x.0),
+            after.map(|x| x.0),
         )
     }
 
@@ -529,7 +589,11 @@ impl ChannelId {
     /// [Manage Messages]: permissions/constant.MANAGE_MESSAGES.html
     #[inline]
     pub fn unpin<M: Into<MessageId>>(&self, message_id: M) -> Result<()> {
-        http::unpin_message(self.0, message_id.into().0)
+        self._unpin(message_id.into())
+    }
+
+    fn _unpin(&self, message_id: MessageId) -> Result<()> {
+        http::unpin_message(self.0, message_id.0)
     }
 
     /// Retrieves the channel's webhooks.
diff --git a/src/model/channel/embed.rs b/src/model/channel/embed.rs
index 8837a8d..bc2d0da 100644
--- a/src/model/channel/embed.rs
+++ b/src/model/channel/embed.rs
@@ -134,9 +134,13 @@ impl EmbedField {
     /// [`value`]: #structfield.value
     pub fn new<T, U>(name: T, value: U, inline: bool) -> Self
         where T: Into<String>, U: Into<String> {
+        Self::_new(name.into(), value.into(), inline)
+    }
+
+    fn _new(name: String, value: String, inline: bool) -> Self {
         Self {
-            name: name.into(),
-            value: value.into(),
+            name: name,
+            value: value,
             inline,
         }
     }
diff --git a/src/model/channel/group.rs b/src/model/channel/group.rs
index 2fc062b..4baa654 100644
--- a/src/model/channel/group.rs
+++ b/src/model/channel/group.rs
@@ -53,9 +53,12 @@ impl Group {
     /// user.
     ///
     /// [`http::add_group_recipient`]: ../http/fn.add_group_recipient.html
+    #[inline]
     pub fn add_recipient<U: Into<UserId>>(&self, user: U) -> Result<()> {
-        let user = user.into();
+        self._add_recipient(user.into())
+    }
 
+    fn _add_recipient(&self, user: UserId) -> Result<()> {
         // If the group already contains the recipient, do nothing.
         if self.recipients.contains_key(&user) {
             return Ok(());
@@ -261,9 +264,12 @@ impl Group {
     /// the group, then nothing is done.
     ///
     /// **Note**: This is only available to the group owner.
+    #[inline]
     pub fn remove_recipient<U: Into<UserId>>(&self, user: U) -> Result<()> {
-        let user = user.into();
+        self._remove_recipient(user.into())
+    }
 
+    fn _remove_recipient(&self, user: UserId) -> Result<()> {
         // If the group does not contain the recipient already, do nothing.
         if !self.recipients.contains_key(&user) {
             return Ok(());
diff --git a/src/model/channel/guild_channel.rs b/src/model/channel/guild_channel.rs
index 533aaf2..2f54fa1 100644
--- a/src/model/channel/guild_channel.rs
+++ b/src/model/channel/guild_channel.rs
@@ -520,7 +520,12 @@ impl GuildChannel {
     /// [Attach Files]: permissions/constant.ATTACH_FILES.html
     /// [Send Messages]: permissions/constant.SEND_MESSAGES.html
     #[cfg(feature = "cache")]
+    #[inline]
     pub fn permissions_for<U: Into<UserId>>(&self, user_id: U) -> Result<Permissions> {
+        self._permissions_for(user_id.into())
+    }
+
+    fn _permissions_for(&self, user_id: UserId) -> Result<Permissions> {
         self.guild()
             .ok_or_else(|| Error::Model(ModelError::GuildNotFound))
             .map(|g| g.read().permissions_in(self.id, user_id))
diff --git a/src/model/channel/message.rs b/src/model/channel/message.rs
index 65cecd6..be17772 100644
--- a/src/model/channel/message.rs
+++ b/src/model/channel/message.rs
@@ -32,7 +32,7 @@ pub struct Message {
     pub channel_id: ChannelId,
     /// The Id of the [`Guild`] that the message was sent in. This value will
     /// only be present if this message was received over the gateway.
-    /// 
+    ///
     /// [`Guild`]: ../guild/struct.Guild.html
     pub guild_id: Option<GuildId>,
     /// The content of the message.
@@ -434,7 +434,12 @@ impl Message {
     /// [`Emoji`]: struct.Emoji.html
     /// [Add Reactions]: permissions/constant.ADD_REACTIONS.html
     /// [permissions]: permissions
+    #[inline]
     pub fn react<R: Into<ReactionType>>(&self, reaction_type: R) -> Result<()> {
+        self._react(&reaction_type.into())
+    }
+
+    fn _react(&self, reaction_type: &ReactionType) -> Result<()> {
         #[cfg(feature = "cache")]
         {
             let req = Permissions::ADD_REACTIONS;
@@ -444,7 +449,7 @@ impl Message {
             }
         }
 
-        http::create_reaction(self.channel_id.0, self.id.0, &reaction_type.into())
+        http::create_reaction(self.channel_id.0, self.id.0, reaction_type)
     }
 
     /// Replies to the user, mentioning them prior to the content in the form
@@ -498,9 +503,13 @@ impl Message {
     /// Checks whether the message mentions passed [`UserId`].
     ///
     /// [`UserId`]: ../../model/id/struct.UserId.html
+    #[inline]
     pub fn mentions_user_id<I: Into<UserId>>(&self, id: I) -> bool {
-        let user_id_to_find = id.into();
-        self.mentions.iter().any(|mentioned_user| mentioned_user.id.0 == user_id_to_find.0)
+        self._mentions_user_id(id.into())
+    }
+
+    fn _mentions_user_id(&self, id: UserId) -> bool {
+        self.mentions.iter().any(|mentioned_user| mentioned_user.id.0 == id.0)
     }
 
     /// Checks whether the message mentions passed [`User`].
diff --git a/src/model/channel/reaction.rs b/src/model/channel/reaction.rs
index 88f687f..0f65e8b 100644
--- a/src/model/channel/reaction.rs
+++ b/src/model/channel/reaction.rs
@@ -151,18 +151,28 @@ impl Reaction {
     /// [`User`]: struct.User.html
     /// [Read Message History]: permissions/constant.READ_MESSAGE_HISTORY.html
     /// [permissions]: permissions
+    #[inline]
     pub fn users<R, U>(&self,
                        reaction_type: R,
                        limit: Option<u8>,
                        after: Option<U>)
                        -> Result<Vec<User>>
         where R: Into<ReactionType>, U: Into<UserId> {
+        self._users(&reaction_type.into(), limit, after.map(Into::into))
+    }
+
+    fn _users(
+        &self,
+        reaction_type: &ReactionType,
+        limit: Option<u8>,
+        after: Option<UserId>,
+    ) -> Result<Vec<User>> {
         http::get_reaction_users(
             self.channel_id.0,
             self.message_id.0,
-            &reaction_type.into(),
+            reaction_type,
             limit.unwrap_or(50),
-            after.map(|u| u.into().0),
+            after.map(|u| u.0),
         )
     }
 }
diff --git a/src/model/guild/guild_id.rs b/src/model/guild/guild_id.rs
index c07a40f..a209369 100644
--- a/src/model/guild/guild_id.rs
+++ b/src/model/guild/guild_id.rs
@@ -48,20 +48,24 @@ impl GuildId {
     /// [`Guild::ban`]: struct.Guild.html#method.ban
     /// [`User`]: struct.User.html
     /// [Ban Members]: permissions/constant.BAN_MEMBERS.html
+    #[inline]
     pub fn ban<U, BO>(&self, user: U, ban_options: &BO) -> Result<()>
         where U: Into<UserId>, BO: BanOptions {
-        let dmd = ban_options.dmd();
+        self._ban(user.into(), (ban_options.dmd(), ban_options.reason()))
+    }
+
+    fn _ban(&self, user: UserId, ban_options: (u8, &str)) -> Result<()> {
+        let (dmd, reason) = ban_options;
+
         if dmd > 7 {
             return Err(Error::Model(ModelError::DeleteMessageDaysAmount(dmd)));
         }
 
-        let reason = ban_options.reason();
-
         if reason.len() > 512 {
             return Err(Error::ExceededLimit(reason.to_string(), 512));
         }
 
-        http::ban_user(self.0, user.into().0, dmd, &*reason)
+        http::ban_user(self.0, user.0, dmd, reason)
     }
 
     /// Gets a list of the guild's bans.
@@ -113,12 +117,22 @@ impl GuildId {
     /// [`GuildChannel`]: struct.GuildChannel.html
     /// [`http::create_channel`]: ../http/fn.create_channel.html
     /// [Manage Channels]: permissions/constant.MANAGE_CHANNELS.html
+    #[inline]
     pub fn create_channel<C>(&self, name: &str, kind: ChannelType, category: C) -> Result<GuildChannel>
         where C: Into<Option<ChannelId>> {
+        self._create_channel(name, kind, category.into())
+    }
+
+    fn _create_channel(
+        &self,
+        name: &str,
+        kind: ChannelType,
+        category: Option<ChannelId>,
+    ) -> Result<GuildChannel> {
         let map = json!({
             "name": name,
             "type": kind as u8,
-            "parent_id": category.into().map(|c| c.0)
+            "parent_id": category.map(|c| c.0)
         });
 
         http::create_channel(self.0, &map)
@@ -141,6 +155,7 @@ impl GuildId {
     /// [`Guild::create_emoji`]: struct.Guild.html#method.create_emoji
     /// [`utils::read_image`]: ../utils/fn.read_image.html
     /// [Manage Emojis]: permissions/constant.MANAGE_EMOJIS.html
+    #[inline]
     pub fn create_emoji(&self, name: &str, image: &str) -> Result<Emoji> {
         let map = json!({
             "name": name,
@@ -155,9 +170,17 @@ impl GuildId {
     /// Requires the [Manage Guild] permission.
     ///
     /// [Manage Guild]: permissions/constant.MANAGE_GUILD.html
+    #[inline]
     pub fn create_integration<I>(&self, integration_id: I, kind: &str) -> Result<()>
         where I: Into<IntegrationId> {
-        let integration_id = integration_id.into();
+        self._create_integration(integration_id.into(), kind)
+    }
+
+    fn _create_integration(
+        &self,
+        integration_id: IntegrationId,
+        kind: &str,
+    ) -> Result<()> {
         let map = json!({
             "id": integration_id.0,
             "type": kind,
@@ -206,7 +229,11 @@ impl GuildId {
     /// [Manage Emojis]: permissions/constant.MANAGE_EMOJIS.html
     #[inline]
     pub fn delete_emoji<E: Into<EmojiId>>(&self, emoji_id: E) -> Result<()> {
-        http::delete_emoji(self.0, emoji_id.into().0)
+        self._delete_emoji(emoji_id.into())
+    }
+
+    fn _delete_emoji(&self, emoji_id: EmojiId) -> Result<()> {
+        http::delete_emoji(self.0, emoji_id.0)
     }
 
     /// Deletes an integration by Id from the guild.
@@ -216,7 +243,11 @@ impl GuildId {
     /// [Manage Guild]: permissions/constant.MANAGE_GUILD.html
     #[inline]
     pub fn delete_integration<I: Into<IntegrationId>>(&self, integration_id: I) -> Result<()> {
-        http::delete_guild_integration(self.0, integration_id.into().0)
+        self._delete_integration(integration_id.into())
+    }
+
+    fn _delete_integration(&self, integration_id: IntegrationId) -> Result<()> {
+        http::delete_guild_integration(self.0, integration_id.0)
     }
 
     /// Deletes a [`Role`] by Id from the guild.
@@ -231,7 +262,11 @@ impl GuildId {
     /// [Manage Roles]: permissions/constant.MANAGE_ROLES.html
     #[inline]
     pub fn delete_role<R: Into<RoleId>>(&self, role_id: R) -> Result<()> {
-        http::delete_role(self.0, role_id.into().0)
+        self._delete_role(role_id.into())
+    }
+
+    fn _delete_role(&self, role_id: RoleId) -> Result<()> {
+        http::delete_role(self.0, role_id.0)
     }
 
     /// Edits the current guild with new data where specified.
@@ -260,12 +295,17 @@ impl GuildId {
     /// [`Emoji`]: struct.Emoji.html
     /// [`Emoji::edit`]: struct.Emoji.html#method.edit
     /// [Manage Emojis]: permissions/constant.MANAGE_EMOJIS.html
+    #[inline]
     pub fn edit_emoji<E: Into<EmojiId>>(&self, emoji_id: E, name: &str) -> Result<Emoji> {
+        self._edit_emoji(emoji_id.into(), name)
+    }
+
+    fn _edit_emoji(&self, emoji_id: EmojiId, name: &str) -> Result<Emoji> {
         let map = json!({
             "name": name,
         });
 
-        http::edit_emoji(self.0, emoji_id.into().0, &map)
+        http::edit_emoji(self.0, emoji_id.0, &map)
     }
 
     /// Edits the properties of member of the guild, such as muting or
@@ -284,9 +324,14 @@ impl GuildId {
     #[inline]
     pub fn edit_member<F, U>(&self, user_id: U, f: F) -> Result<()>
         where F: FnOnce(EditMember) -> EditMember, U: Into<UserId> {
+        self._edit_member(user_id.into(), f)
+    }
+
+    fn _edit_member<F>(&self, user_id: UserId, f: F) -> Result<()>
+        where F: FnOnce(EditMember) -> EditMember {
         let map = utils::vecmap_to_json_map(f(EditMember::default()).0);
 
-        http::edit_member(self.0, user_id.into().0, &map)
+        http::edit_member(self.0, user_id.0, &map)
     }
 
     /// Edits the current user's nickname for the guild.
@@ -320,9 +365,14 @@ impl GuildId {
     #[inline]
     pub fn edit_role<F, R>(&self, role_id: R, f: F) -> Result<Role>
         where F: FnOnce(EditRole) -> EditRole, R: Into<RoleId> {
+        self._edit_role(role_id.into(), f)
+    }
+
+    fn _edit_role<F>(&self, role_id: RoleId, f: F) -> Result<Role>
+        where F: FnOnce(EditRole) -> EditRole {
         let map = utils::vecmap_to_json_map(f(EditRole::default()).0);
 
-        http::edit_role(self.0, role_id.into().0, &map)
+        http::edit_role(self.0, role_id.0, &map)
     }
 
     /// Edits the order of [`Role`]s
@@ -342,7 +392,15 @@ impl GuildId {
     #[inline]
     pub fn edit_role_position<R>(&self, role_id: R, position: u64) -> Result<Vec<Role>>
         where R: Into<RoleId> {
-        http::edit_role_position(self.0, role_id.into().0, position)
+        self._edit_role_position(role_id.into(), position)
+    }
+
+    fn _edit_role_position(
+        &self,
+        role_id: RoleId,
+        position: u64,
+    ) -> Result<Vec<Role>> {
+        http::edit_role_position(self.0, role_id.0, position)
     }
 
 
@@ -392,7 +450,11 @@ impl GuildId {
     /// [`Member`]: struct.Member.html
     #[inline]
     pub fn member<U: Into<UserId>>(&self, user_id: U) -> Result<Member> {
-        http::get_member(self.0, user_id.into().0)
+        self._member(user_id.into())
+    }
+
+    fn _member(&self, user_id: UserId) -> Result<Member> {
+        http::get_member(self.0, user_id.0)
     }
 
     /// Gets a list of the guild's members.
@@ -405,7 +467,11 @@ impl GuildId {
     #[inline]
     pub fn members<U>(&self, limit: Option<u64>, after: Option<U>) -> Result<Vec<Member>>
         where U: Into<UserId> {
-        http::get_guild_members(self.0, limit, after.map(|x| x.into().0))
+        self._members(limit, after.map(Into::into))
+    }
+
+    fn _members(&self, limit: Option<u64>, after: Option<UserId>) -> Result<Vec<Member>> {
+        http::get_guild_members(self.0, limit, after.map(|x| x.0))
     }
 
     /// Moves a member to a specific voice channel.
@@ -413,15 +479,24 @@ impl GuildId {
     /// Requires the [Move Members] permission.
     ///
     /// [Move Members]: permissions/constant.MOVE_MEMBERS.html
+    #[inline]
     pub fn move_member<C, U>(&self, user_id: U, channel_id: C) -> Result<()>
         where C: Into<ChannelId>, U: Into<UserId> {
+        self._move_member(user_id.into(), channel_id.into())
+    }
+
+    fn _move_member(
+        &self,
+        user_id: UserId,
+        channel_id: ChannelId,
+    ) -> Result<()> {
         let mut map = Map::new();
         map.insert(
             "channel_id".to_string(),
-            Value::Number(Number::from(channel_id.into().0)),
+            Value::Number(Number::from(channel_id.0)),
         );
 
-        http::edit_member(self.0, user_id.into().0, &map)
+        http::edit_member(self.0, user_id.0, &map)
     }
 
     /// Gets the number of [`Member`]s that would be pruned with the given
@@ -447,8 +522,13 @@ impl GuildId {
     /// Although not required, you should specify all channels' positions,
     /// regardless of whether they were updated. Otherwise, positioning can
     /// sometimes get weird.
+    #[inline]
     pub fn reorder_channels<It>(&self, channels: It) -> Result<()>
         where It: IntoIterator<Item = (ChannelId, u64)> {
+        self._reorder_channels(channels.into_iter().collect())
+    }
+
+    fn _reorder_channels(&self, channels: Vec<(ChannelId, u64)>) -> Result<()> {
         let items = channels.into_iter().map(|(id, pos)| json!({
             "id": id,
             "position": pos,
@@ -503,7 +583,14 @@ impl GuildId {
     /// [Manage Guild]: permissions/constant.MANAGE_GUILD.html
     #[inline]
     pub fn start_integration_sync<I: Into<IntegrationId>>(&self, integration_id: I) -> Result<()> {
-        http::start_integration_sync(self.0, integration_id.into().0)
+        self._start_integration_sync(integration_id.into())
+    }
+
+    fn _start_integration_sync(
+        &self,
+        integration_id: IntegrationId,
+    ) -> Result<()> {
+        http::start_integration_sync(self.0, integration_id.0)
     }
 
     /// Starts a prune of [`Member`]s.
@@ -532,7 +619,11 @@ impl GuildId {
     /// [Ban Members]: permissions/constant.BAN_MEMBERS.html
     #[inline]
     pub fn unban<U: Into<UserId>>(&self, user_id: U) -> Result<()> {
-        http::remove_ban(self.0, user_id.into().0)
+        self._unban(user_id.into())
+    }
+
+    fn _unban(&self, user_id: UserId) -> Result<()> {
+        http::remove_ban(self.0, user_id.0)
     }
 
     /// Retrieve's the guild's vanity URL.
diff --git a/src/model/guild/member.rs b/src/model/guild/member.rs
index c95c07f..8101700 100644
--- a/src/model/guild/member.rs
+++ b/src/model/guild/member.rs
@@ -85,9 +85,13 @@ impl Member {
     /// [`Role`]: struct.Role.html
     /// [Manage Roles]: permissions/constant.MANAGE_ROLES.html
     #[cfg(feature = "cache")]
+    #[inline]
     pub fn add_role<R: Into<RoleId>>(&mut self, role_id: R) -> Result<()> {
-        let role_id = role_id.into();
+        self._add_role(role_id.into())
+    }
 
+    #[cfg(feature = "cache")]
+    fn _add_role(&mut self, role_id: RoleId) -> Result<()> {
         if self.roles.contains(&role_id) {
             return Ok(());
         }
@@ -140,14 +144,17 @@ impl Member {
     ///
     /// [Ban Members]: permissions/constant.BAN_MEMBERS.html
     #[cfg(feature = "cache")]
+    #[inline]
     pub fn ban<BO: BanOptions>(&self, ban_options: &BO) -> Result<()> {
-        let dmd = ban_options.dmd();
+        self._ban(ban_options.dmd(), ban_options.reason())
+    }
+
+    #[cfg(feature = "cache")]
+    fn _ban(&self, dmd: u8, reason: &str) -> Result<()> {
         if dmd > 7 {
             return Err(Error::Model(ModelError::DeleteMessageDaysAmount(dmd)));
         }
 
-        let reason = ban_options.reason();
-
         if reason.len() > 512 {
             return Err(Error::ExceededLimit(reason.to_string(), 512));
         }
@@ -368,9 +375,13 @@ impl Member {
     /// [`Role`]: struct.Role.html
     /// [Manage Roles]: permissions/constant.MANAGE_ROLES.html
     #[cfg(feature = "cache")]
+    #[inline]
     pub fn remove_role<R: Into<RoleId>>(&mut self, role_id: R) -> Result<()> {
-        let role_id = role_id.into();
+        self._remove_role(role_id.into())
+    }
 
+    #[cfg(feature = "cache")]
+    fn _remove_role(&mut self, role_id: RoleId) -> Result<()> {
         if !self.roles.contains(&role_id) {
             return Ok(());
         }
diff --git a/src/model/guild/mod.rs b/src/model/guild/mod.rs
index 9e4d8ef..4fc7079 100644
--- a/src/model/guild/mod.rs
+++ b/src/model/guild/mod.rs
@@ -229,9 +229,12 @@ impl Guild {
     /// [`Guild::ban`]: struct.Guild.html#method.ban
     /// [`User`]: struct.User.html
     /// [Ban Members]: permissions/constant.BAN_MEMBERS.html
+    #[inline]
     pub fn ban<U: Into<UserId>, BO: BanOptions>(&self, user: U, options: &BO) -> Result<()> {
-        let user = user.into();
+        self._ban(user.into(), options)
+    }
 
+    fn _ban<BO: BanOptions>(&self, user: UserId, options: &BO) -> Result<()> {
         #[cfg(feature = "cache")]
         {
             let req = Permissions::BAN_MEMBERS;
@@ -669,11 +672,18 @@ impl Guild {
     /// If both user IDs are the same, `None` is returned. If one of the users
     /// is the guild owner, their ID is returned.
     #[cfg(feature = "cache")]
+    #[inline]
     pub fn greater_member_hierarchy<T, U>(&self, lhs_id: T, rhs_id: U)
         -> Option<UserId> where T: Into<UserId>, U: Into<UserId> {
-        let lhs_id = lhs_id.into();
-        let rhs_id = rhs_id.into();
+        self._greater_member_hierarchy(lhs_id.into(), rhs_id.into())
+    }
 
+    #[cfg(feature = "cache")]
+    fn _greater_member_hierarchy(
+        &self,
+        lhs_id: UserId,
+        rhs_id: UserId,
+    ) -> Option<UserId> {
         // Check that the IDs are the same. If they are, neither is greater.
         if lhs_id == rhs_id {
             return None;
@@ -1106,10 +1116,13 @@ impl Guild {
     /// Calculate a [`Member`]'s permissions in the guild.
     ///
     /// [`Member`]: struct.Member.html
+    #[inline]
     pub fn member_permissions<U>(&self, user_id: U) -> Permissions
         where U: Into<UserId> {
-        let user_id = user_id.into();
+        self._member_permissions(user_id.into())
+    }
 
+    fn _member_permissions(&self, user_id: UserId) -> Permissions {
         if user_id == self.owner_id {
             return Permissions::all();
         }
@@ -1179,17 +1192,22 @@ impl Guild {
     /// Calculate a [`User`]'s permissions in a given channel in the guild.
     ///
     /// [`User`]: struct.User.html
+    #[inline]
     pub fn permissions_in<C, U>(&self, channel_id: C, user_id: U) -> Permissions
         where C: Into<ChannelId>, U: Into<UserId> {
-        let user_id = user_id.into();
+        self._permissions_in(channel_id.into(), user_id.into())
+    }
 
+    fn _permissions_in(
+        &self,
+        channel_id: ChannelId,
+        user_id: UserId,
+    ) -> Permissions {
         // The owner has all permissions in all cases.
         if user_id == self.owner_id {
             return Permissions::all();
         }
 
-        let channel_id = channel_id.into();
-
         // Start by retrieving the @everyone role's permissions.
         let everyone = match self.roles.get(&RoleId(self.id.0)) {
             Some(everyone) => everyone,
diff --git a/src/model/invite.rs b/src/model/invite.rs
index b93b231..2bbd5d9 100644
--- a/src/model/invite.rs
+++ b/src/model/invite.rs
@@ -70,8 +70,11 @@ impl Invite {
     /// [permission]: permissions/index.html
     pub fn create<C, F>(channel_id: C, f: F) -> Result<RichInvite>
         where C: Into<ChannelId>, F: FnOnce(CreateInvite) -> CreateInvite {
-        let channel_id = channel_id.into();
+        Self::_create(channel_id.into(), f)
+    }
 
+    fn _create<F>(channel_id: ChannelId, f: F) -> Result<RichInvite>
+        where F: FnOnce(CreateInvite) -> CreateInvite {
         #[cfg(feature = "cache")]
         {
             let req = Permissions::CREATE_INVITE;
diff --git a/src/model/user.rs b/src/model/user.rs
index 330f319..48891d3 100644
--- a/src/model/user.rs
+++ b/src/model/user.rs
@@ -580,10 +580,12 @@ impl User {
     // no-cache would warn on guild_id.
     pub fn has_role<G, R>(&self, guild: G, role: R) -> bool
         where G: Into<GuildContainer>, R: Into<RoleId> {
-        let role_id = role.into();
+        self._has_role(guild.into(), role.into())
+    }
 
+    fn _has_role(&self, guild: GuildContainer, role: RoleId) -> bool {
         match guild.into() {
-            GuildContainer::Guild(guild) => guild.roles.contains_key(&role_id),
+            GuildContainer::Guild(guild) => guild.roles.contains_key(&role),
             GuildContainer::Id(_guild_id) => {
                 feature_cache! {{
                     CACHE.read()
@@ -591,7 +593,7 @@ impl User {
                         .get(&_guild_id)
                         .map(|g| {
                             g.read().members.get(&self.id)
-                                .map(|m| m.roles.contains(&role_id))
+                                .map(|m| m.roles.contains(&role))
                                 .unwrap_or(false)
                         })
                         .unwrap_or(false)