fetch_instruction can just return a reference.

cthulahoops · cthulahoops · commit 786eb2cbfbae · 2019-02-28T08:33:43.000Z
diff --git a/vm/src/frame.rs b/vm/src/frame.rs
@@ -141,10 +141,8 @@ impl Frame {
         value
     }
 
-    pub fn fetch_instruction(&self) -> bytecode::Instruction {
-        // TODO: an immutable reference is enough, we should not
-        // clone the instruction.
-        let ins2 = self.code.instructions[*self.lasti.borrow()].clone();
+    pub fn fetch_instruction(&self) -> &bytecode::Instruction {
+        let ins2 = &self.code.instructions[*self.lasti.borrow()];
         *self.lasti.borrow_mut() += 1;
         ins2
     }

Original file line number	Diff line number	Diff line change
`@@ -141,10 +141,8 @@ impl Frame {`
`141`	`141`	`value`
`142`	`142`	`}`
`143`	`143`
`144`		`- pub fn fetch_instruction(&self) -> bytecode::Instruction {`
`145`		`- // TODO: an immutable reference is enough, we should not`
`146`		`- // clone the instruction.`
`147`		`- let ins2 = self.code.instructions[*self.lasti.borrow()].clone();`
	`144`	`+ pub fn fetch_instruction(&self) -> &bytecode::Instruction {`
	`145`	`+ let ins2 = &self.code.instructions[*self.lasti.borrow()];`
`148`	`146`	`*self.lasti.borrow_mut() += 1;`
`149`	`147`	`ins2`
`150`	`148`	`}`