From 42d3fde0af7adf0386b6071e2c217f571d0c46ed Mon Sep 17 00:00:00 2001
From: Stephen Chung <schungx@live.com>
Date: Sun, 26 Sep 2021 21:30:33 +0800
Subject: [PATCH] Fix no_closure build.

---
 src/engine.rs   | 6 ++++--
 src/optimize.rs | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/engine.rs b/src/engine.rs
index 0b8b2740..7b891f2f 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -2090,7 +2090,7 @@ impl Engine {
             // `... ${...} ...`
             Expr::InterpolatedString(x, pos) => {
                 let mut pos = *pos;
-                let mut result: Dynamic = self.const_empty_string().clone().into();
+                let mut result: Dynamic = self.const_empty_string().into();
 
                 for expr in x.iter() {
                     let item = self.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?;
@@ -3041,7 +3041,9 @@ impl Engine {
         match result {
             // Concentrate all empty strings into one instance to save memory
             #[cfg(feature = "no_closure")]
-            Ok(r) if r.as_str_ref().map_or(false, &str::is_empty) => Ok(self.empty_string().into()),
+            Ok(r) if r.as_str_ref().map_or(false, &str::is_empty) => {
+                Ok(self.const_empty_string().into())
+            }
             // Concentrate all empty strings into one instance to save memory
             #[cfg(not(feature = "no_closure"))]
             Ok(r) if !r.is_shared() && r.as_str_ref().map_or(false, &str::is_empty) => {
diff --git a/src/optimize.rs b/src/optimize.rs
index d4ec1945..22878f5b 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -822,7 +822,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
         // ``
         Expr::InterpolatedString(x, pos) if x.is_empty() => {
             state.set_dirty();
-            *expr = Expr::StringConstant(state.engine.const_empty_string().clone(), *pos);
+            *expr = Expr::StringConstant(state.engine.const_empty_string(), *pos);
         }
         // `...`
         Expr::InterpolatedString(x, _) if x.len() == 1 && matches!(x[0], Expr::StringConstant(_, _)) => {