Use cfg-if for cfgs in wasm

Cargo.toml

@@ -13,6 +13,9 @@ edition = "2018"
 now = [ "time" ]
 wasm-bindgen = ["js-sys", "wasm-bindgen_rs", "web-sys"]
 
+[dependencies]
+cfg-if = "0.1"
+
 [target.'cfg(not(any(feature = "stdweb", feature = "wasm-bindgen")))'.dependencies]
 time = { version = "0.1", optional = true }
 

src/lib.rs

@@ -1,48 +1,20 @@
-#[cfg(all(
-    any(
+cfg_if::cfg_if! {
+    if #[cfg(any(
         all(target_arch = "wasm32", not(target_os = "wasi")),
         target_arch = "asmjs"
-    ),
-    all(feature = "stdweb", not(feature = "wasm-bindgen"))
-))]
-#[macro_use]
-extern crate stdweb;
+    ))] {
+        #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+        #[macro_use]
+        extern crate stdweb;
 
-#[cfg(not(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-)))]
-pub use crate::native::Instant;
-
-#[cfg(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-))]
-pub use crate::wasm::Instant;
-
-#[cfg(not(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-)))]
-#[cfg(feature = "now")]
-pub use crate::native::now;
-
-#[cfg(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-))]
-#[cfg(feature = "now")]
-pub use crate::wasm::now;
-
-pub use std::time::Duration;
-
-#[cfg(not(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-)))]
-mod native;
-#[cfg(any(
-    all(target_arch = "wasm32", not(target_os = "wasi")),
-    target_arch = "asmjs"
-))]
-mod wasm;
+        mod wasm;
+        pub use wasm::Instant;
+        #[cfg(feature = "now")]
+        pub use crate::wasm::now;
+    } else {
+        mod native;
+        pub use native::Instant;
+        #[cfg(feature = "now")]
+        pub use native::now;
+    }
+}