Make more functions const

CHANGELOG.md

@@ -10,6 +10,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - `rocksdb-storage` feature and associated items (See [PR #761](https://github.com/teloxide/teloxide/pull/761) for reasoning) [**BC**]
 
+## Changed
+
+- The following functions were made `const`:
+  - `Dialogue::{new, chat_id}`
+  - `Polling::builder`
+  - `StatefulListener::new_with_hints`
+  - `CommandDescriptions::new`
+  - `respond`
+
 ## 0.11.1 - 2022-10-31
 
 ### Added

crates/teloxide-core/src/bot.rs

@@ -130,7 +130,7 @@ impl Bot {
     /// [`reqwest::Client`]: https://docs.rs/reqwest/0.10.1/reqwest/struct.Client.html
     /// [issue 223]: https://github.com/teloxide/teloxide/issues/223
     pub fn from_env_with_client(client: Client) -> Self {
-        Self::with_client(&get_env(TELOXIDE_TOKEN), client)
+        Self::with_client(get_env(TELOXIDE_TOKEN), client)
     }
 
     /// Sets a custom API URL.

crates/teloxide-core/src/net.rs

@@ -43,7 +43,7 @@ pub fn client_from_env() -> reqwest::Client {
     let builder = default_reqwest_settings();
 
     match std::env::var(TELOXIDE_PROXY).ok() {
-        Some(proxy) => builder.proxy(Proxy::all(&proxy).expect("reqwest::Proxy creation failed")),
+        Some(proxy) => builder.proxy(Proxy::all(proxy).expect("reqwest::Proxy creation failed")),
         None => builder,
     }
     .build()

crates/teloxide/src/dispatching/dialogue.rs

@@ -141,13 +141,13 @@ where
     /// Constructs a new dialogue with `storage` (where dialogues are stored)
     /// and `chat_id` of a current dialogue.
     #[must_use]
-    pub fn new(storage: Arc<S>, chat_id: ChatId) -> Self {
+    pub const fn new(storage: Arc<S>, chat_id: ChatId) -> Self {
         Self { storage, chat_id, _phantom: PhantomData }
     }
 
     /// Returns a chat ID associated with this dialogue.
     #[must_use]
-    pub fn chat_id(&self) -> ChatId {
+    pub const fn chat_id(&self) -> ChatId {
         self.chat_id
     }
 

crates/teloxide/src/dispatching/update_listeners.rs

@@ -133,7 +133,7 @@ pub trait AsUpdateStream<'a> {
 }
 
 #[inline(always)]
-pub(crate) fn assert_update_listener<L>(listener: L) -> L
+pub(crate) const fn assert_update_listener<L>(listener: L) -> L
 where
     L: UpdateListener,
 {

crates/teloxide/src/dispatching/update_listeners/polling.rs

@@ -250,7 +250,7 @@ where
     <R as Requester>::GetUpdates: Send,
 {
     /// Returns a builder for polling update listener.
-    pub fn builder(bot: R) -> PollingBuilder<R> {
+    pub const fn builder(bot: R) -> PollingBuilder<R> {
         PollingBuilder {
             bot,
             timeout: None,

crates/teloxide/src/dispatching/update_listeners/stateful_listener.rs

@@ -55,7 +55,7 @@ impl<St, Assf, Sf> StatefulListener<St, Assf, Sf, Haufn<St>, Thfn<St>> {
 
 impl<St, Assf, Sf, Hauf, Thf> StatefulListener<St, Assf, Sf, Hauf, Thf> {
     /// Creates a new stateful listener from its components.
-    pub fn new_with_hints(
+    pub const fn new_with_hints(
         state: St,
         stream: Assf,
         stop_token: Sf,

crates/teloxide/src/utils/command.rs

@@ -298,7 +298,7 @@ pub struct CommandDescription<'a> {
 impl<'a> CommandDescriptions<'a> {
     /// Creates new [`CommandDescriptions`] from a list of command descriptions.
     #[must_use]
-    pub fn new(descriptions: &'a [CommandDescription<'a>]) -> Self {
+    pub const fn new(descriptions: &'a [CommandDescription<'a>]) -> Self {
         Self { global_description: None, descriptions, bot_username: None }
     }