Use cfg_if! in a separated private function for the ifa_ifu field.

Author: mwanner

src/ifaddrs.rs

@@ -30,6 +30,18 @@ pub struct InterfaceAddress {
     pub destination: Option<SockAddr>,
 }
 
+cfg_if! {
+    if #[cfg(any(target_os = "emscripten", target_os = "fuchsia", target_os="linux"))] {
+        fn get_ifu_from_sockaddr(info: &libc::ifaddrs) -> *const libc::sockaddr {
+            info.ifa_ifu
+        }
+    } else {
+        fn get_ifu_from_sockaddr(info: &libc::ifaddrs) -> *const libc::sockaddr {
+            info.ifa_dstaddr;
+        }
+    }
+}
+
 impl InterfaceAddress {
     /// Create an `InterfaceAddress` from the libc struct.
     fn from_libc_ifaddrs(info: &libc::ifaddrs) -> InterfaceAddress {
@@ -45,14 +57,7 @@ impl InterfaceAddress {
             destination: None,
         };
 
-        let ifu : *mut libc::sockaddr;
-
-        #[cfg(any(target_os = "linux", target_os = "emscripten", target_os = "fuchsia"))]
-        { ifu = info.ifa_ifu; }
-
-        #[cfg(not(any(target_os = "linux", target_os = "emscripten", target_os = "fuchsia")))]
-        { ifu = info.ifa_dstaddr; }
-
+        let ifu = get_ifu_from_sockaddr(info);
         if addr.flags.contains(IFF_POINTOPOINT) {
             addr.destination = unsafe { SockAddr::from_libc_sockaddr(ifu) };
         } else if addr.flags.contains(IFF_BROADCAST) {

src/sys/socket/addr.rs

@@ -706,7 +706,7 @@ impl SockAddr {
     }
 
     /// Creates a `SockAddr` struct from libc's sockaddr.
-    pub unsafe fn from_libc_sockaddr(addr: *mut libc::sockaddr) -> Option<SockAddr> {
+    pub unsafe fn from_libc_sockaddr(addr: *const libc::sockaddr) -> Option<SockAddr> {
         if addr.is_null() {
             None
         } else {