diff --git a/compiler/noirc_driver/src/abi_gen.rs b/compiler/noirc_driver/src/abi_gen.rs
index 9d0d64b6300..e546cd822b7 100644
--- a/compiler/noirc_driver/src/abi_gen.rs
+++ b/compiler/noirc_driver/src/abi_gen.rs
@@ -33,7 +33,7 @@ pub(super) fn compute_function_abi(
 ) -> (Vec<AbiParameter>, Option<AbiType>) {
     let func_meta = context.def_interner.function_meta(func_id);
 
-    let (parameters, return_type) = func_meta.into_function_signature();
+    let (parameters, return_type) = func_meta.function_signature();
     let parameters = into_abi_params(context, parameters);
     let return_type = return_type.map(|typ| AbiType::from_type(context, &typ));
     (parameters, return_type)
diff --git a/compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs b/compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs
index 8ada3faf756..e87ef34088d 100644
--- a/compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs
+++ b/compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs
@@ -542,6 +542,7 @@ pub(crate) fn check_methods_signatures(
 
             // TODO: This is not right since it may bind generic return types
             trait_method.return_type().unify(&resolved_return_type, &mut typecheck_errors, || {
+                let impl_method = resolver.interner.function_meta(func_id);
                 let ret_type_span = impl_method.return_type.get_type().span;
                 let expr_span = ret_type_span.expect("return type must always have a span");
 
diff --git a/compiler/noirc_frontend/src/hir/mod.rs b/compiler/noirc_frontend/src/hir/mod.rs
index fc3ed06260f..c62f357167f 100644
--- a/compiler/noirc_frontend/src/hir/mod.rs
+++ b/compiler/noirc_frontend/src/hir/mod.rs
@@ -152,7 +152,7 @@ impl Context<'_> {
         None
     }
 
-    pub fn function_meta(&self, func_id: &FuncId) -> FuncMeta {
+    pub fn function_meta(&self, func_id: &FuncId) -> &FuncMeta {
         self.def_interner.function_meta(func_id)
     }
 
diff --git a/compiler/noirc_frontend/src/hir/type_check/expr.rs b/compiler/noirc_frontend/src/hir/type_check/expr.rs
index caa77852560..50ed98a794a 100644
--- a/compiler/noirc_frontend/src/hir/type_check/expr.rs
+++ b/compiler/noirc_frontend/src/hir/type_check/expr.rs
@@ -190,10 +190,11 @@ impl<'interner> TypeChecker<'interner> {
                                 // Automatically add `&mut` if the method expects a mutable reference and
                                 // the object is not already one.
                                 if *func_id != FuncId::dummy_id() {
-                                    let func_meta = self.interner.function_meta(func_id);
+                                    let function_type =
+                                        self.interner.function_meta(func_id).typ.clone();
                                     self.try_add_mutable_reference_to_object(
                                         &mut method_call,
-                                        &func_meta.typ,
+                                        &function_type,
                                         &mut args,
                                     );
                                 }
@@ -561,7 +562,7 @@ impl<'interner> TypeChecker<'interner> {
 
                 let func_meta = self.interner.function_meta(&func_id);
                 let param_len = func_meta.parameters.len();
-                (func_meta.typ, param_len)
+                (func_meta.typ.clone(), param_len)
             }
             HirMethodReference::TraitMethodId(method) => {
                 let the_trait = self.interner.get_trait(method.trait_id);
@@ -916,7 +917,7 @@ impl<'interner> TypeChecker<'interner> {
                     &self.current_function.expect("unexpected method outside a function"),
                 );
 
-                for constraint in func_meta.trait_constraints {
+                for constraint in &func_meta.trait_constraints {
                     if *object_type == constraint.typ {
                         if let Some(the_trait) = self.interner.try_get_trait(constraint.trait_id) {
                             for (method_index, method) in the_trait.methods.iter().enumerate() {
diff --git a/compiler/noirc_frontend/src/hir/type_check/mod.rs b/compiler/noirc_frontend/src/hir/type_check/mod.rs
index 092e8631f1b..c05c233fe34 100644
--- a/compiler/noirc_frontend/src/hir/type_check/mod.rs
+++ b/compiler/noirc_frontend/src/hir/type_check/mod.rs
@@ -50,10 +50,15 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
     type_checker.current_function = Some(func_id);
 
     let meta = type_checker.interner.function_meta(&func_id);
+    let parameters = meta.parameters.clone();
+    let expected_return_type = meta.return_type.clone();
+    let expected_trait_constraints = meta.trait_constraints.clone();
+    let name_span = meta.name.location.span;
+
     let mut errors = Vec::new();
 
     // Temporarily add any impls in this function's `where` clause to scope
-    for constraint in &meta.trait_constraints {
+    for constraint in &expected_trait_constraints {
         let object = constraint.typ.clone();
         let trait_id = constraint.trait_id;
 
@@ -61,7 +66,7 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
             if let Some(the_trait) = type_checker.interner.try_get_trait(trait_id) {
                 let trait_name = the_trait.name.to_string();
                 let typ = constraint.typ.clone();
-                let span = meta.name.location.span;
+                let span = name_span;
                 errors.push(TypeCheckError::UnneededTraitConstraint { trait_name, typ, span });
             }
         }
@@ -70,7 +75,7 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
     // Bind each parameter to its annotated type.
     // This is locally obvious, but it must be bound here so that the
     // Definition object of the parameter in the NodeInterner is given the correct type.
-    for param in meta.parameters.into_iter() {
+    for param in parameters {
         type_checker.bind_pattern(&param.0, param.1);
     }
 
@@ -93,7 +98,7 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
     errors.append(&mut type_checker.errors);
 
     // Now remove all the `where` clause constraints we added
-    for constraint in &meta.trait_constraints {
+    for constraint in &expected_trait_constraints {
         interner.remove_assumed_trait_implementations_for_trait(constraint.trait_id);
     }
 
@@ -107,7 +112,7 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
                     expected: declared_return_type.clone(),
                     actual: function_last_type,
                     span: func_span,
-                    source: Source::Return(meta.return_type, expr_span),
+                    source: Source::Return(expected_return_type, expr_span),
                 };
                 errors.push(error);
             }
@@ -122,7 +127,7 @@ pub fn type_check_func(interner: &mut NodeInterner, func_id: FuncId) -> Vec<Type
                         expected: declared_return_type.clone(),
                         actual: function_last_type.clone(),
                         span: func_span,
-                        source: Source::Return(meta.return_type, expr_span),
+                        source: Source::Return(expected_return_type, expr_span),
                     };
 
                     if empty_function {
diff --git a/compiler/noirc_frontend/src/hir_def/function.rs b/compiler/noirc_frontend/src/hir_def/function.rs
index 085bda107e3..9fff301f5f7 100644
--- a/compiler/noirc_frontend/src/hir_def/function.rs
+++ b/compiler/noirc_frontend/src/hir_def/function.rs
@@ -131,22 +131,12 @@ impl FuncMeta {
         }
     }
 
-    pub fn into_function_signature(self) -> FunctionSignature {
-        // Doesn't use `self.return_type()` so we aren't working with references and don't need a `clone()`
-        let return_type = match self.typ {
-            Type::Function(_, ret, _env) => *ret,
-            Type::Forall(_, typ) => match *typ {
-                Type::Function(_, ret, _env) => *ret,
-                _ => unreachable!(),
-            },
-            _ => unreachable!(),
-        };
-        let return_type = match return_type {
+    pub fn function_signature(&self) -> FunctionSignature {
+        let return_type = match self.return_type() {
             Type::Unit => None,
-            typ => Some(typ),
+            typ => Some(typ.clone()),
         };
-
-        (self.parameters.0, return_type)
+        (self.parameters.0.clone(), return_type)
     }
 
     /// Gives the (uninstantiated) return type of this function.
diff --git a/compiler/noirc_frontend/src/monomorphization/mod.rs b/compiler/noirc_frontend/src/monomorphization/mod.rs
index bb0972987e4..c24a2290011 100644
--- a/compiler/noirc_frontend/src/monomorphization/mod.rs
+++ b/compiler/noirc_frontend/src/monomorphization/mod.rs
@@ -20,7 +20,7 @@ use std::{
 use crate::{
     hir_def::{
         expr::*,
-        function::{FuncMeta, FunctionSignature, Parameters},
+        function::{FunctionSignature, Parameters},
         stmt::{HirAssignStatement, HirLValue, HirLetStatement, HirPattern, HirStatement},
         types,
     },
@@ -106,14 +106,14 @@ pub fn monomorphize(main: node_interner::FuncId, interner: &NodeInterner) -> Pro
     }
 
     let functions = vecmap(monomorphizer.finished_functions, |(_, f)| f);
-    let FuncMeta { return_distinctness, return_visibility, .. } = interner.function_meta(&main);
+    let meta = interner.function_meta(&main);
 
     Program::new(
         functions,
         function_sig,
-        return_distinctness,
+        meta.return_distinctness,
         monomorphizer.return_location,
-        return_visibility,
+        meta.return_visibility,
     )
 }
 
@@ -217,7 +217,7 @@ impl<'interner> Monomorphizer<'interner> {
                 },
             );
         let main_meta = self.interner.function_meta(&main_id);
-        main_meta.into_function_signature()
+        main_meta.function_signature()
     }
 
     fn function(&mut self, f: node_interner::FuncId, id: FuncId) {
@@ -237,7 +237,7 @@ impl<'interner> Monomorphizer<'interner> {
             _ => meta.return_type(),
         });
 
-        let parameters = self.parameters(meta.parameters);
+        let parameters = self.parameters(&meta.parameters);
 
         let body = self.expr(body_expr_id);
         let unconstrained = modifiers.is_unconstrained
@@ -254,17 +254,17 @@ impl<'interner> Monomorphizer<'interner> {
 
     /// Monomorphize each parameter, expanding tuple/struct patterns into multiple parameters
     /// and binding any generic types found.
-    fn parameters(&mut self, params: Parameters) -> Vec<(ast::LocalId, bool, String, ast::Type)> {
+    fn parameters(&mut self, params: &Parameters) -> Vec<(ast::LocalId, bool, String, ast::Type)> {
         let mut new_params = Vec::with_capacity(params.len());
-        for parameter in params {
-            self.parameter(parameter.0, &parameter.1, &mut new_params);
+        for (parameter, typ, _) in &params.0 {
+            self.parameter(parameter, typ, &mut new_params);
         }
         new_params
     }
 
     fn parameter(
         &mut self,
-        param: HirPattern,
+        param: &HirPattern,
         typ: &HirType,
         new_params: &mut Vec<(ast::LocalId, bool, String, ast::Type)>,
     ) {
@@ -276,11 +276,11 @@ impl<'interner> Monomorphizer<'interner> {
                 new_params.push((new_id, definition.mutable, name, self.convert_type(typ)));
                 self.define_local(ident.id, new_id);
             }
-            HirPattern::Mutable(pattern, _) => self.parameter(*pattern, typ, new_params),
+            HirPattern::Mutable(pattern, _) => self.parameter(pattern, typ, new_params),
             HirPattern::Tuple(fields, _) => {
                 let tuple_field_types = unwrap_tuple_type(typ);
 
-                for (field, typ) in fields.into_iter().zip(tuple_field_types) {
+                for (field, typ) in fields.iter().zip(tuple_field_types) {
                     self.parameter(field, &typ, new_params);
                 }
             }
@@ -288,7 +288,8 @@ impl<'interner> Monomorphizer<'interner> {
                 let struct_field_types = unwrap_struct_type(typ);
                 assert_eq!(struct_field_types.len(), fields.len());
 
-                let mut fields = btree_map(fields, |(name, field)| (name.0.contents, field));
+                let mut fields =
+                    btree_map(fields, |(name, field)| (name.0.contents.clone(), field));
 
                 // Iterate over `struct_field_types` since `unwrap_struct_type` will always
                 // return the fields in the order defined by the struct type.
@@ -1183,7 +1184,7 @@ impl<'interner> Monomorphizer<'interner> {
         let parameters =
             vecmap(lambda.parameters, |(pattern, typ)| (pattern, typ, Visibility::Private)).into();
 
-        let parameters = self.parameters(parameters);
+        let parameters = self.parameters(&parameters);
         let body = self.expr(lambda.body);
 
         let id = self.next_function_id();
@@ -1234,7 +1235,7 @@ impl<'interner> Monomorphizer<'interner> {
         let parameters =
             vecmap(lambda.parameters, |(pattern, typ)| (pattern, typ, Visibility::Private)).into();
 
-        let mut converted_parameters = self.parameters(parameters);
+        let mut converted_parameters = self.parameters(&parameters);
 
         let id = self.next_function_id();
         let name = lambda_name.to_owned();
diff --git a/compiler/noirc_frontend/src/node_interner.rs b/compiler/noirc_frontend/src/node_interner.rs
index 261b11158cf..9d310b595de 100644
--- a/compiler/noirc_frontend/src/node_interner.rs
+++ b/compiler/noirc_frontend/src/node_interner.rs
@@ -768,12 +768,12 @@ impl NodeInterner {
     }
 
     /// Returns the interned meta data corresponding to `func_id`
-    pub fn function_meta(&self, func_id: &FuncId) -> FuncMeta {
-        self.func_meta.get(func_id).cloned().expect("ice: all function ids should have metadata")
+    pub fn function_meta(&self, func_id: &FuncId) -> &FuncMeta {
+        self.func_meta.get(func_id).expect("ice: all function ids should have metadata")
     }
 
-    pub fn try_function_meta(&self, func_id: &FuncId) -> Option<FuncMeta> {
-        self.func_meta.get(func_id).cloned()
+    pub fn try_function_meta(&self, func_id: &FuncId) -> Option<&FuncMeta> {
+        self.func_meta.get(func_id)
     }
 
     pub fn function_ident(&self, func_id: &FuncId) -> crate::Ident {