From 72326bd96f262ab6e9490a07c6664100a43c0ea1 Mon Sep 17 00:00:00 2001
From: sharks <sharks@localhost.localdomain>
Date: Tue, 27 Mar 2018 21:58:10 -0500
Subject: [PATCH] use an option

---
 src/common.rs | 6 +++---
 src/ipv4.rs   | 7 +++----
 src/ipv6.rs   | 7 +++----
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/common.rs b/src/common.rs
index 904e52f..17ac193 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -32,12 +32,12 @@ impl Error for IpNetworkError {
     }
 }
 
-pub fn cidr_parts(cidr: &str) -> Result<(&str, &str), IpNetworkError> {
+pub fn cidr_parts(cidr: &str) -> Result<(&str, Option<&str>), IpNetworkError> {
     let parts = cidr.split('/').collect::<Vec<&str>>();
     if parts.len() == 1 {
-        Ok((parts[0], ""))
+        Ok((parts[0], None))
     } else if parts.len() == 2 {
-        Ok((parts[0], parts[1]))
+        Ok((parts[0], Some(parts[1])))
     } else {
         Err(IpNetworkError::InvalidCidrFormat(format!(
             "CIDR must contain a single '/': {}",
diff --git a/src/ipv4.rs b/src/ipv4.rs
index c5cc660..e0fd721 100644
--- a/src/ipv4.rs
+++ b/src/ipv4.rs
@@ -192,10 +192,9 @@ 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 = if prefix_str.is_empty() {
-            IPV4_BITS
-        } else {
-            parse_prefix(prefix_str, IPV4_BITS)?
+        let prefix = match prefix_str {
+            Some(v) => parse_prefix(v, IPV4_BITS)?,
+            None => IPV4_BITS,
         };
         Ipv4Network::new(addr, prefix)
     }
diff --git a/src/ipv6.rs b/src/ipv6.rs
index cbee659..711423e 100644
--- a/src/ipv6.rs
+++ b/src/ipv6.rs
@@ -172,10 +172,9 @@ 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 = if prefix_str.is_empty() {
-            IPV6_BITS
-        } else {
-            parse_prefix(prefix_str, IPV6_BITS)?
+        let prefix = match prefix_str {
+            Some(v) => parse_prefix(v, IPV6_BITS)?,
+            None => IPV6_BITS,
         };
         Ipv6Network::new(addr, prefix)
     }