refactor: clippy::must_use_candidate

Cargo.toml

@@ -29,7 +29,6 @@ struct_excessive_bools = "allow" # due to Telegram API
 
 # TODO: remove and fix (or allow explicitly on the specific problem)
 missing_errors_doc = "allow"
-must_use_candidate = "allow"
 option_if_let_else = "allow"
 significant_drop_tightening = "allow"
 single_match_else = "allow"

src/api/async_telegram_api_impl.rs

@@ -11,6 +11,7 @@ use tokio::fs::File;
 use typed_builder::TypedBuilder;
 
 #[derive(Debug, Clone, TypedBuilder)]
+#[must_use = "API needs to be used in order to be useful"]
 pub struct AsyncApi {
     #[builder(setter(into))]
     pub api_url: String,

src/api/telegram_api_impl.rs

@@ -9,6 +9,7 @@ use typed_builder::TypedBuilder;
 use ureq::Response;
 
 #[derive(Debug, Clone, TypedBuilder)]
+#[must_use = "API needs to be used in order to be useful"]
 pub struct Api {
     #[builder(setter(into))]
     pub api_url: String,
@@ -20,7 +21,6 @@ impl Api {
     /// Create a new `Api`. You can use `Api::builder()` for more options.
     pub fn new(api_key: &str) -> Self {
         let api_url = format!("{}{api_key}", super::BASE_API_URL);
-
         Self::builder().api_url(api_url).build()
     }
 

src/parse_mode.rs

@@ -29,6 +29,7 @@ impl FromStr for ParseMode {
 }
 
 impl ParseMode {
+    #[must_use]
     pub const fn to_str(self) -> &'static str {
         match self {
             Self::Html => "HTML",