From 6f086ae46bcdf0d12922b25d939b1b5ace0ccad0 Mon Sep 17 00:00:00 2001
From: Christopher Serr <christopher.serr@gmail.com>
Date: Sun, 4 Aug 2019 17:47:51 +0200
Subject: [PATCH] Implement Support for no_std

sid doesn't actually need std. It can just use core + alloc.
---
 Cargo.toml       |  2 +-
 src/id.rs        |  8 ++++----
 src/id_list.rs   |  7 ++++---
 src/id_range.rs  |  8 ++++----
 src/id_vector.rs | 12 ++++++------
 src/lib.rs       | 30 ++++++++++++++++--------------
 6 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d53dd11..c45a182 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,4 +10,4 @@ repository = "https://github.com/nical/sid"
 name = "sid"
 
 [dependencies]
-num-traits = "0.2"
+num-traits = { version = "0.2", default-features = false }
diff --git a/src/id.rs b/src/id.rs
index dfd6de6..5c4b889 100644
--- a/src/id.rs
+++ b/src/id.rs
@@ -1,8 +1,8 @@
 use {IdRange, IntegerHandle, Identifier, FromUsize, ToUsize};
-use std::marker::PhantomData;
-use std::fmt;
-use std::ops::{Add, Sub};
-use std::hash::{Hash, Hasher};
+use core::marker::PhantomData;
+use core::fmt;
+use core::ops::{Add, Sub};
+use core::hash::{Hash, Hasher};
 use num_traits::One;
 
 #[repr(C)]
diff --git a/src/id_list.rs b/src/id_list.rs
index ddf3390..4cafe2a 100644
--- a/src/id_list.rs
+++ b/src/id_list.rs
@@ -1,6 +1,7 @@
 use super::{Identifier, FromUsize};
-use std::marker::PhantomData;
-use std::ops;
+use core::marker::PhantomData;
+use core::ops;
+use alloc::vec::Vec;
 
 /// A trait that defines how to choose the null (or invalid) Id.
 pub trait NullId<ID> {
@@ -237,7 +238,7 @@ struct MagicValue;
 #[cfg(test)]
 impl NullId<TestId> for MagicValue {
     fn null_id() -> TestId {
-        return FromUsize::from_usize(::std::u32::MAX as usize);
+        return FromUsize::from_usize(::core::u32::MAX as usize);
     }
 }
 
diff --git a/src/id_range.rs b/src/id_range.rs
index c8f925b..f54fc80 100644
--- a/src/id_range.rs
+++ b/src/id_range.rs
@@ -1,8 +1,8 @@
 use {Id, IntegerHandle, FromUsize};
-use std::marker::PhantomData;
-use std::fmt;
-use std::ops;
-use std::cmp;
+use core::marker::PhantomData;
+use core::fmt;
+use core::ops;
+use core::cmp;
 use num_traits::Zero;
 
 pub struct IdRange<T, H = u32> {
diff --git a/src/id_vector.rs b/src/id_vector.rs
index 4e79bd4..ae096b1 100644
--- a/src/id_vector.rs
+++ b/src/id_vector.rs
@@ -1,10 +1,10 @@
 use {Identifier, FromUsize, ToUsize, IdRange};
-use std::default::Default;
-use std::slice;
-use std::vec;
-use std::marker::PhantomData;
-use std::ops;
-use std::iter::IntoIterator;
+use core::default::Default;
+use core::slice;
+use alloc::{vec, vec::Vec};
+use core::marker::PhantomData;
+use core::ops;
+use core::iter::IntoIterator;
 use num_traits::Zero;
 
 /// Similar to Vec except that it is indexed using an Id rather than an usize index.
diff --git a/src/lib.rs b/src/lib.rs
index 5ef1560..e9f24bd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,18 +1,21 @@
+#![no_std]
+
+extern crate alloc;
 extern crate num_traits;
 
-use std::cmp;
-use std::ops::{Add, Sub};
-use num_traits::{Zero, One};
+use num_traits::{One, Zero};
+use core::cmp;
+use core::ops::{Add, Sub};
 
 mod id;
+mod id_list;
 mod id_range;
 mod id_vector;
-mod id_list;
 
-pub use id_vector::{IdSlice, MutIdSlice, IdVec};
-pub use id_list::{IdFreeList, NullId, NoneAsNullId};
 pub use id::Id;
+pub use id_list::{IdFreeList, NoneAsNullId, NullId};
 pub use id_range::{IdRange, ReverseIdRange};
+pub use id_vector::{IdSlice, IdVec, MutIdSlice};
 
 pub trait FromUsize {
     fn from_usize(idx: usize) -> Self;
@@ -22,8 +25,8 @@ pub trait ToUsize {
     fn to_usize(&self) -> usize;
 }
 
-pub trait IntegerHandle
-    : Copy
+pub trait IntegerHandle:
+    Copy
     + Clone
     + Add<Output = Self>
     + Sub<Output = Self>
@@ -33,7 +36,8 @@ pub trait IntegerHandle
     + FromUsize
     + ToUsize
     + Zero
-    + One {
+    + One
+{
 }
 
 pub trait Identifier: Copy + FromUsize + ToUsize + PartialEq {
@@ -212,7 +216,6 @@ impl IntegerHandle for i32 {}
 impl IntegerHandle for i64 {}
 impl IntegerHandle for isize {}
 
-
 /*
 // TODO: remove it or implement traits manually
 
@@ -226,8 +229,8 @@ pub struct GenId<T, H: Copy, G> {
     pub gen: G,
 }
 
-impl<T, H: Copy + std::fmt::Display, G: std::fmt::Display> std::fmt::Debug for GenId<T, H, G> {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+impl<T, H: Copy + core::fmt::Display, G: core::fmt::Display> core::fmt::Debug for GenId<T, H, G> {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
         write!(f, "GenId#{}({})", self.id.handle, self.gen)
     }
 }
@@ -272,7 +275,6 @@ impl<T, H: Copy, G: Generation> Generation for GenId<T, H, G> {
 }
 */
 
-
 #[test]
 fn test_copy_id() {
     #[derive(Debug)]
@@ -294,7 +296,7 @@ fn test_copy_id() {
 
 #[test]
 fn test_reverese_id_range() {
-    use std::iter::FromIterator;
+    use core::iter::FromIterator;
     fn range(first: u16, count: u16) -> IdRange<u16, u16> {
         IdRange::new(first..(first + count))
     }