Add const unsafe new_unchecked to Ipv4Network & Ipv6Network (#185)

* Add const unsafe `new_unchecked` to `Ipv4Network` & `Ipv6Network`

* New tests added for `new_unchecked` functions

src/ipv4.rs

@@ -74,6 +74,12 @@ impl Ipv4Network {
         }
     }
 
+    /// Constructs without checking prefix a new `Ipv4Network` from any `Ipv4Addr,
+    /// and a prefix denoting the network size.
+    pub const unsafe fn new_unchecked(addr: Ipv4Addr, prefix: u8) -> Ipv4Network {
+        Ipv4Network { addr, prefix }
+    }
+
     /// Constructs a new `Ipv4Network` from a network address and a network mask.
     ///
     /// If the netmask is not valid this will return an `IpNetworkError::InvalidPrefix`.
@@ -362,6 +368,14 @@ mod test {
         assert!(net.is_err());
     }
 
+    #[test]
+    fn create_unchecked_v4() {
+        let cidr = unsafe { Ipv4Network::new_unchecked(Ipv4Addr::new(77, 88, 21, 11), 24) };
+        assert_eq!(cidr.prefix(), 24);
+        let cidr = unsafe { Ipv4Network::new_unchecked(Ipv4Addr::new(0, 0, 0, 0), 33) };
+        assert_eq!(cidr.prefix(), 33);
+    }
+
     #[test]
     fn parse_v4_24bit() {
         let cidr: Ipv4Network = "127.1.0.0/24".parse().unwrap();

src/ipv6.rs

@@ -85,6 +85,12 @@ impl Ipv6Network {
         }
     }
 
+    /// Constructs without checking prefix a new `Ipv6Network` from any `Ipv6Addr,
+    /// and a prefix denoting the network size.
+    pub const unsafe fn new_unchecked(addr: Ipv6Addr, prefix: u8) -> Ipv6Network {
+        Ipv6Network { addr, prefix }
+    }
+
     /// Constructs a new `Ipv6Network` from a network address and a network mask.
     ///
     /// If the netmask is not valid this will return an `IpNetworkError::InvalidPrefix`.
@@ -410,6 +416,15 @@ mod test {
         assert!(cidr.is_err());
     }
 
+    #[test]
+    fn create_unchecked_v6() {
+        let cidr = unsafe { Ipv6Network::new_unchecked(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 24) };
+        assert_eq!(cidr.prefix(), 24);
+        let cidr =
+            unsafe { Ipv6Network::new_unchecked(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 129) };
+        assert_eq!(cidr.prefix(), 129);
+    }
+
     #[test]
     fn parse_v6() {
         let cidr: Ipv6Network = "::1/0".parse().unwrap();

src/lib.rs

@@ -3,7 +3,6 @@
 #![crate_type = "lib"]
 #![deny(
     missing_debug_implementations,
-    unsafe_code,
     unused_extern_crates,
     unused_import_braces
 )]