fix: ensure at least one required feature is enabled

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         run: cargo install cargo-hack --locked
 
       - name: cargo hack
-        run: cargo hack check --feature-powerset --no-dev-deps
+        run: cargo hack check --feature-powerset --skip serde,full-codecs --depth 4 --no-dev-deps
       - name: cargo test
         run: cargo test
       - name: cargo fmt

src/content.rs

@@ -159,7 +159,7 @@ impl ContentType {
 	/// ```
 	#[must_use]
 	pub fn as_str(&self) -> &'static str {
-		match self {
+		match *self {
 			#[cfg(feature = "json")]
 			Self::Json => "application/json",
 			#[cfg(feature = "msgpack")]

src/lib.rs

@@ -1,6 +1,18 @@
 #![forbid(unsafe_code)]
 #![warn(clippy::pedantic)]
 #![allow(clippy::module_name_repetitions)]
+#![cfg_attr(
+	not(any(
+		feature = "json",
+		feature = "msgpack",
+		feature = "bincode",
+		feature = "bitcode",
+		feature = "cbor",
+		feature = "yaml",
+		feature = "toml"
+	)),
+	allow(unreachable_code, unused_variables)
+)]
 #![doc = include_str!("../README.md")]
 
 mod content;

src/rejection.rs

@@ -1,4 +1,8 @@
-use axum::{extract::rejection::BytesRejection, http::StatusCode, response::Response};
+use axum::{
+	extract::rejection::BytesRejection,
+	http::StatusCode,
+	response::{IntoResponse, Response},
+};
 
 use crate::{ContentType, IntoCodecResponse};