Support no_std

Author: nchiasson

Cargo.toml

@@ -19,6 +19,7 @@ path = "src/lib.rs"
 [[bin]]
 name = "fcidr"
 path = "src/main.rs"
+required-features = ["std"]
 
 [badges]
 github = { repository = "nicholaschiasson/fcidr" }
@@ -32,3 +33,8 @@ serde = { version = "1.0", optional = true }
 serde_json = "1.0"
 assert_cmd = "2.0"
 predicates = "3.0"
+
+[features]
+default = []
+std = []
+serde = ["dep:serde"]

src/cidr.rs

@@ -1,4 +1,7 @@
-use std::{
+extern crate alloc;
+
+use alloc::{format, string::ToString};
+use core::{
     fmt::{Debug, Display},
     net::Ipv4Addr,
     str::FromStr,
@@ -135,7 +138,7 @@ impl Default for Cidr {
 }
 
 impl Display for Cidr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
         write!(f, "{}/{}", self.network, self.prefix)
     }
 }

src/error.rs

@@ -1,4 +1,5 @@
-use std::{error, fmt};
+use alloc::string::String;
+use core::{error, fmt::Display};
 
 #[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
 pub enum Error {
@@ -7,8 +8,8 @@ pub enum Error {
     Parse(String),
 }
 
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::fmt::Result {
+impl Display for Error {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "{self:?}")
     }
 }

src/fcidr.rs

@@ -1,4 +1,5 @@
-use std::{cell::RefCell, rc::Rc};
+use alloc::{borrow::ToOwned, rc::Rc, vec::Vec};
+use core::cell::RefCell;
 
 use crate::Cidr;
 

src/lib.rs

@@ -1,3 +1,5 @@
+extern crate alloc;
+
 mod cidr;
 mod error;
 mod fcidr;

src/serde.rs

@@ -1,7 +1,7 @@
 #![cfg(feature = "serde")]
 #![cfg_attr(doc_cfg, doc(cfg(feature = "serde")))]
 
-use std::str::FromStr;
+use core::str::FromStr;
 
 use serde::{de::Visitor, ser::SerializeSeq, Deserialize, Serialize};