From 09308e93b8d2d74589754d62ba3531eb225c2f67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=91=A8=E7=9D=BF?= <zrufo747@outlook.com>
Date: Wed, 24 Sep 2025 09:20:37 +0800
Subject: [PATCH] feat: add no_std support
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Signed-off-by: 周睿 <zrufo747@outlook.com>
---
 CHANGELOG.md                           | 3 +++
 Cargo.toml                             | 6 +++++-
 src/allocation_engine/interval_tree.rs | 2 ++
 src/id_allocator.rs                    | 2 +-
 src/lib.rs                             | 6 ++++++
 5 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d3f837..8623fd5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 ## Upcoming version
 
 ### Added
+
+- Support for no_std environments.
+
 ### Changed
 ### Fixed
 ### Removed
diff --git a/Cargo.toml b/Cargo.toml
index 97367bf..d363de7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,11 @@ keywords = ["resources", "allocation", "address", "virt"]
 license = "Apache-2.0 OR BSD-3-Clause"
 edition = "2018"
 
+[features]
+default = ["std"]
+std = []
+
 [dependencies]
 libc = "0.2.39"
-thiserror = "2.0"
+thiserror = {version= "2.0", default-features = false}
 serde = { version = "1.0.137", optional = true, features = ["derive"] }
diff --git a/src/allocation_engine/interval_tree.rs b/src/allocation_engine/interval_tree.rs
index cbb56fa..d06c022 100644
--- a/src/allocation_engine/interval_tree.rs
+++ b/src/allocation_engine/interval_tree.rs
@@ -4,6 +4,8 @@
 
 use std::cmp::{max, Ordering};
 
+use alloc::boxed::Box;
+
 use crate::{AllocPolicy, Constraint, Error, RangeInclusive, Result};
 
 /// Returns the first multiple of `alignment` that is lower or equal to the
diff --git a/src/id_allocator.rs b/src/id_allocator.rs
index 86037ff..5914dee 100644
--- a/src/id_allocator.rs
+++ b/src/id_allocator.rs
@@ -8,7 +8,7 @@
 //! that can be abstracted to an integer.
 
 use crate::{Error, Result};
-use std::collections::BTreeSet;
+use alloc::collections::BTreeSet;
 
 /// An unique ID allocator that allows management of IDs in a given interval.
 // Internal representation of IdAllocator. Contains the ends of the interval
diff --git a/src/lib.rs b/src/lib.rs
index e7eccd3..bbf2acb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -74,6 +74,12 @@
 //! ```
 
 #![deny(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+extern crate alloc;
+
+#[cfg(not(feature = "std"))]
+extern crate core as std;
 
 mod address_allocator;
 /// Allocation engine used by address allocator.