Merge singlecore and multicore configs

Cargo.toml

@@ -16,6 +16,7 @@ crate-type = ["cdylib", "lib", "staticlib"]
 rand = "0.4"
 bit-vec = "0.4.4"
 futures = "0.1"
+cfg-if = "0.1.7"
 
 pairing = { git = 'https://github.com/matterinc/pairing', tag = "0.16.2" }
 #pairing = { path = "../pairing" }

src/lib.rs

@@ -1,5 +1,7 @@
 #![allow(unused_imports)]
+#[macro_use]
 
+extern crate cfg_if;
 extern crate pairing as pairing_import;
 extern crate rand;
 extern crate bit_vec;
@@ -20,18 +22,18 @@ mod multiexp;
 #[cfg(test)]
 mod tests;
 
-#[cfg(feature = "multicore")]
-mod multicore;
-
-#[cfg(feature = "singlecore")]
-mod singlecore;
-
-mod worker {
-    #[cfg(feature = "multicore")]
-    pub use crate::multicore::*;
-
-    #[cfg(feature = "singlecore")]
-    pub use crate::singlecore::*;
+cfg_if! {
+    if #[cfg(feature = "multicore")] {
+        mod multicore;
+        mod worker {
+            pub use crate::multicore::*;
+        }
+    } else {
+        mod singlecore;
+        mod worker {
+            pub use crate::singlecore::*;
+        }
+    }
 }
 
 pub mod pairing {