Fix no_std

src/lib.rs

@@ -9,6 +9,7 @@ pub mod stored;
 use core::fmt::Debug;
 use core::{iter, mem};
 
+use alloc::format;
 use alloc::{boxed::Box, string::String, vec::Vec};
 pub use modified::*;
 use sha2::{Digest, Sha256};

src/stored/memory_db.rs

@@ -1,6 +1,6 @@
 use core::cell::RefCell;
 
-use alloc::collections::BTreeMap;
+use alloc::{collections::BTreeMap, format, string::String};
 
 use crate::{Branch, Leaf};
 

src/stored/merkle.rs

@@ -1,5 +1,4 @@
-use core::ops::Deref;
-use std::cell::RefCell;
+use core::{cell::RefCell, ops::Deref};
 
 use alloc::{boxed::Box, format, string::String, vec::Vec};
 use bumpalo::Bump;