Use `alloc` instead of `std` for `bounds_to_string` stuff
@@ -4,10 +4,10 @@ use crate::utils::distance_between;
use core::fmt::Debug;
#[cfg(feature = "std")]
-use std::string::String;
+use alloc::string::String;
#[cfg(feature = "std")]
-use std::format;
+use alloc::format;
use core::intrinsics;
use core::iter::{FusedIterator, TrustedLen};
