If there is no prefix, default to number of bits ipv4/32, ipv6/128

src/common.rs

@@ -35,7 +35,7 @@ impl Error for IpNetworkError {
 pub fn cidr_parts(cidr: &str) -> Result<(&str, &str), IpNetworkError> {
     let parts = cidr.split('/').collect::<Vec<&str>>();
     if parts.len() == 1 {
-        Ok((parts[0], "32"))
+        Ok((parts[0], ""))
     } else if parts.len() == 2 {
         Ok((parts[0], parts[1]))
     } else {

src/ipv4.rs

@@ -190,7 +190,14 @@ impl FromStr for Ipv4Network {
     fn from_str(s: &str) -> Result<Ipv4Network, IpNetworkError> {
         let (addr_str, prefix_str) = cidr_parts(s)?;
         let addr = parse_addr(addr_str)?;
-        let prefix = parse_prefix(prefix_str, IPV4_BITS)?;
+        let prefix = parse_prefix(
+            if prefix_str.is_empty() {
+                IPV4_BITS.to_string()
+            } else {
+                prefix_str
+            },
+            IPV4_BITS,
+        )?;
         Ipv4Network::new(addr, prefix)
     }
 }

src/ipv6.rs

@@ -170,7 +170,14 @@ impl FromStr for Ipv6Network {
         let (addr_str, prefix_str) = cidr_parts(s)?;
         let addr = Ipv6Addr::from_str(addr_str)
             .map_err(|_| IpNetworkError::InvalidAddr(addr_str.to_string()))?;
-        let prefix = parse_prefix(prefix_str, IPV6_BITS)?;
+        let prefix = parse_prefix(
+            if prefix_str.is_empty() {
+                IPV6_BITS.to_string()
+            } else {
+                prefix_str
+            },
+            IPV6_BITS,
+        )?;
         Ipv6Network::new(addr, prefix)
     }
 }