Use doc(cfg) for docs.rs

Also, remove some usage of `cfg_if!` since the macro seemed to be
preventing `cfg(doc)` from being auto-populated.

Author: tesaguri

oauth1-request/Cargo.toml

@@ -14,6 +14,9 @@ description = """
 Yet yet yet another OAuth 1.0 client library.
 """
 
+[package.metadata.docs.rs]
+rustdoc-args = ["--cfg", "docsrs"]
+
 [dependencies]
 base64 = "0.13"
 bitflags = "1"

oauth1-request/src/lib.rs

@@ -88,7 +88,10 @@
 //!
 //! See [`Request`][oauth1_request_derive::Request] for more details on the derive macro.
 
+#![cfg_attr(docsrs, feature(doc_cfg, doc_cfg_hide))]
 #![doc(html_root_url = "https://docs.rs/oauth1-request/0.5.1")]
+// Prevent `oauth-credentials/alloc` feature from showing up on re-exports.
+#![cfg_attr(docsrs, doc(cfg_hide(feature = "alloc")))]
 #![deny(broken_intra_doc_links)]
 #![warn(missing_docs, rust_2018_idioms)]
 

oauth1-request/src/serializer/auth.rs

@@ -53,13 +53,9 @@ options! {
 /// A version of `Signer` that uses the `PLAINTEXT` signature method.
 pub type PlaintextAuthorizer<'a> = Authorizer<'a, Plaintext>;
 
-cfg_if::cfg_if! {
-    if #[cfg(feature = "hmac-sha1")] {
-        use crate::signature_method::HmacSha1;
-        /// A version of `Signer` that uses the `HMAC-SHA1` signature method.
-        pub type HmacSha1Authorizer<'a> = Authorizer<'a, HmacSha1>;
-    }
-}
+/// A version of `Signer` that uses the `HMAC-SHA1` signature method.
+#[cfg(feature = "hmac-sha1")]
+pub type HmacSha1Authorizer<'a> = Authorizer<'a, crate::signature_method::HmacSha1>;
 
 impl<'a, SM: SignatureMethod> Authorizer<'a, SM> {
     /// Creates an `Authorizer`.

oauth1-request/src/signature_method.rs

@@ -6,19 +6,16 @@
 //! So the module provides an abstraction over signature methods so that users can implement those
 //! custom methods by themselves.
 
-cfg_if::cfg_if! {
-    if #[cfg(feature = "hmac-sha1")] {
-        pub mod hmac_sha1;
-        pub use self::hmac_sha1::HmacSha1;
-    }
-}
-
+#[cfg(feature = "hmac-sha1")]
+pub mod hmac_sha1;
 pub mod identity;
 pub mod plaintext;
 
 #[cfg(feature = "either")]
 mod either;
 
+#[cfg(feature = "hmac-sha1")]
+pub use self::hmac_sha1::HmacSha1;
 pub use self::identity::Identity;
 pub use self::plaintext::Plaintext;