Make compiler happy for linux and OSX

Author: vagrant

HISTORY.rst

@@ -2,7 +2,7 @@
 History
 =======
 
-0.5.0 (2017-05-19)
+0.5.0 (2017-05-21)
 ------------------
 
 * First release on PyPI.

trust_pypi_example/rust/src/lib.rs

@@ -14,6 +14,15 @@ pub extern "C" fn is_prime(n: *const c_int) -> c_int {
     1
 } 
 
+#[allow(dead_code)]
+#[no_mangle]
+pub extern "C" fn spare() {
+    // https://github.com/rust-lang/rust/issues/38281 😂
+    println!("");
+    //adding this (doesn't have to be named "spare") makes the compilation work.
+    // you don't even need to add this function signature where you're using these functions.
+}
+
 #[test]
 fn test_is_prime() {
     let not_prime = 12;
@@ -22,4 +31,4 @@ fn test_is_prime() {
     let _false: c_int = 0;
     assert_eq!(is_prime(not_prime as *const c_int), _false);
     assert_eq!(is_prime(is_a_prime as *const c_int), _true);
-}
+}