Stabilize `IpAddr::is_ipv4` and `is_ipv6` as const

Insta-stabilize the methods `is_ipv4` and `is_ipv6` of `IpAddr`.

Possible because of the recent stabilization of const control flow.

Also adds a test for these methods in a const context.

2 files changed, 17 insertions, 2 deletions

diff --git a/library/std/src/net/ip.rs b/library/std/src/net/ip.rs
index bb3ece4c273..714ff78777c 100644
--- a/library/std/src/net/ip.rs
+++ b/library/std/src/net/ip.rs
@@ -263,8 +263,9 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(203, 0, 113, 6)).is_ipv4(), true);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0)).is_ipv4(), false);
     /// ```
+    #[rustc_const_stable(feature = "const_ip", since = "1.48.0")]
     #[stable(feature = "ipaddr_checker", since = "1.16.0")]
-    pub fn is_ipv4(&self) -> bool {
+    pub const fn is_ipv4(&self) -> bool {
         matches!(self, IpAddr::V4(_))
     }
 
@@ -281,8 +282,9 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V4(Ipv4Addr::new(203, 0, 113, 6)).is_ipv6(), false);
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 0)).is_ipv6(), true);
     /// ```
+    #[rustc_const_stable(feature = "const_ip", since = "1.48.0")]
     #[stable(feature = "ipaddr_checker", since = "1.16.0")]
-    pub fn is_ipv6(&self) -> bool {
+    pub const fn is_ipv6(&self) -> bool {
         matches!(self, IpAddr::V6(_))
     }
 }
diff --git a/src/test/ui/consts/std/net/ip.rs b/src/test/ui/consts/std/net/ip.rs
new file mode 100644
index 00000000000..6730946577d
--- /dev/null
+++ b/src/test/ui/consts/std/net/ip.rs
@@ -0,0 +1,13 @@
+// run-pass
+
+use std::net::{IpAddr, Ipv4Addr};
+
+fn main() {
+    const IP_ADDRESS : IpAddr = IpAddr::V4(Ipv4Addr::LOCALHOST);
+
+    const IS_IP_V4 : bool = IP_ADDRESS.is_ipv4();
+    assert!(IS_IP_V4);
+
+    const IS_IP_V6 : bool = IP_ADDRESS.is_ipv6();
+    assert!(!IS_IP_V6);
+}