Small fixups.

src/any.rs

@@ -18,7 +18,6 @@ use crate::stdlib::{
     boxed::Box,
     collections::HashMap,
     fmt,
-    hash::Hash,
     string::String,
     vec::Vec,
 };

src/engine.rs

@@ -710,7 +710,7 @@ impl Engine {
         /// This function restores the first argument that was replaced by `normalize_first_arg_of_method_call`.
         fn restore_first_arg<'a>(old_this_ptr: Option<&'a mut Dynamic>, args: &mut FnCallArgs<'a>) {
             if let Some(this_pointer) = old_this_ptr {
-                mem::replace(args.get_mut(0).unwrap(), this_pointer);
+                args[0] = this_pointer;
             }
         }
 

src/module.rs

@@ -30,6 +30,7 @@ use crate::stdlib::{
 };
 
 #[cfg(not(feature = "no_std"))]
+#[cfg(feature = "sync")]
 use crate::stdlib::sync::RwLock;
 
 /// Return type of module-level Rust function.

src/packages/arithmetic.rs

@@ -8,6 +8,7 @@ use crate::token::Position;
 use crate::parser::FLOAT;
 
 #[cfg(not(feature = "no_float"))]
+#[cfg(feature = "no_std")]
 use num_traits::*;
 
 use num_traits::{

src/packages/math_basic.rs

@@ -7,6 +7,7 @@ use crate::token::Position;
 use crate::parser::FLOAT;
 
 #[cfg(not(feature = "no_float"))]
+#[cfg(feature = "no_std")]
 use num_traits::*;
 
 use crate::stdlib::{boxed::Box, format, i32, i64};