Applies review changes.

Replaces `IdentUnique` usage with `(Ident, TyFunctionSig)`.
Borrowed TyFunctionSig from 3878.

sway-core/src/decl_engine/mapping.rs

@@ -1,6 +1,8 @@
 use std::{collections::BTreeMap, fmt};
 
-use sway_types::{Ident, IdentUnique};
+use sway_types::Ident;
+
+use crate::language::ty::TyFunctionSig;
 
 use super::DeclId;
 
@@ -10,7 +12,7 @@ type DestinationDecl = DeclId;
 /// The [DeclMapping] is used to create a mapping between a [SourceDecl] (LHS)
 /// and a [DestinationDecl] (RHS).
 pub(crate) struct DeclMapping {
-    pub(crate) mapping: Vec<(SourceDecl, DestinationDecl)>,
+    mapping: Vec<(SourceDecl, DestinationDecl)>,
 }
 
 impl fmt::Display for DeclMapping {
@@ -46,6 +48,14 @@ impl DeclMapping {
         self.mapping.is_empty()
     }
 
+    pub(crate) fn mapping(&self) -> Vec<(SourceDecl, DestinationDecl)> {
+        self.mapping.clone()
+    }
+
+    pub(crate) fn from_mapping(mapping: Vec<(SourceDecl, DestinationDecl)>) -> DeclMapping {
+        DeclMapping { mapping }
+    }
+
     pub(crate) fn from_stub_and_impld_decl_ids(
         stub_decl_ids: BTreeMap<Ident, DeclId>,
         impld_decl_ids: BTreeMap<Ident, DeclId>,
@@ -59,13 +69,13 @@ impl DeclMapping {
         DeclMapping { mapping }
     }
 
-    pub(crate) fn from_stub_and_impld_decl_ids_unique(
+    pub(crate) fn from_stub_and_impld_decl_ids_with_function_sig(
         stub_decl_ids: BTreeMap<Ident, DeclId>,
-        new_decl_ids: BTreeMap<IdentUnique, DeclId>,
+        new_decl_ids: BTreeMap<(Ident, TyFunctionSig), DeclId>,
     ) -> DeclMapping {
         let mut mapping = vec![];
         for (stub_decl_name, stub_decl_id) in stub_decl_ids.into_iter() {
-            for (new_decl_name, new_decl_id) in new_decl_ids.iter() {
+            for ((new_decl_name, _), new_decl_id) in new_decl_ids.iter() {
                 if new_decl_name.as_str() != stub_decl_name.as_str() {
                     continue;
                 }

sway-core/src/language/ty/declaration/function.rs

@@ -448,3 +448,22 @@ impl TyFunctionParameter {
         self.name.as_str() == "self"
     }
 }
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct TyFunctionSig {
+    pub return_type: TypeId,
+    pub parameters: Vec<TypeId>,
+}
+
+impl TyFunctionSig {
+    pub fn from_fn_decl(fn_decl: &TyFunctionDeclaration) -> Self {
+        Self {
+            return_type: fn_decl.return_type,
+            parameters: fn_decl
+                .parameters
+                .iter()
+                .map(|p| p.type_id)
+                .collect::<Vec<_>>(),
+        }
+    }
+}

sway-core/src/language/ty/expression/expression_variant.rs

@@ -635,7 +635,7 @@ impl ReplaceDecls for TyExpressionVariant {
                 // declaration to be replaced by two different implemented function
                 // declaration. The code below filters the correct implementation to use.
                 let mut decl_mapping_filtered = vec![];
-                'decls: for (orig_decl_id, dest_decl_id) in decl_mapping.mapping.clone() {
+                'decls: for (orig_decl_id, dest_decl_id) in decl_mapping.mapping() {
                     let all_parents = engines
                         .de()
                         .find_all_parents(engines, function_decl_id.clone());
@@ -663,17 +663,13 @@ impl ReplaceDecls for TyExpressionVariant {
                     }
                 }
 
-                // No function with same arguemnt type were found so we try to replace decls as usual
+                // No function with same argument type were found so we try to replace decls as usual
                 if decl_mapping_filtered.is_empty() {
-                    decl_mapping_filtered = decl_mapping.mapping.clone();
+                    decl_mapping_filtered = decl_mapping.mapping();
                 }
 
-                function_decl_id.replace_decls(
-                    &DeclMapping {
-                        mapping: decl_mapping_filtered,
-                    },
-                    engines,
-                );
+                function_decl_id
+                    .replace_decls(&DeclMapping::from_mapping(decl_mapping_filtered), engines);
                 let new_decl_id = function_decl_id
                     .clone()
                     .replace_decls_and_insert_new(decl_mapping, engines);

sway-core/src/type_system/type_parameter.rs

@@ -2,13 +2,16 @@ use crate::{
     decl_engine::*,
     engine_threading::*,
     error::*,
-    language::{ty, CallPath},
+    language::{
+        ty::{self, TyFunctionSig},
+        CallPath,
+    },
     semantic_analysis::*,
     type_system::*,
 };
 
 use sway_error::error::CompileError;
-use sway_types::{ident::Ident, span::Span, IdentUnique, Spanned};
+use sway_types::{ident::Ident, span::Span, Spanned};
 
 use fuel_abi_types::program_abi;
 
@@ -191,7 +194,7 @@ impl TypeParameter {
         let mut errors = vec![];
 
         let mut original_method_ids: BTreeMap<Ident, DeclId> = BTreeMap::new();
-        let mut impld_method_ids: BTreeMap<IdentUnique, DeclId> = BTreeMap::new();
+        let mut impld_method_ids: BTreeMap<(Ident, TyFunctionSig), DeclId> = BTreeMap::new();
 
         for type_param in type_parameters.iter() {
             let TypeParameter {
@@ -229,13 +232,16 @@ impl TypeParameter {
                 );
                 original_method_ids.extend(trait_original_method_ids);
                 for (key, value) in trait_impld_method_ids {
-                    impld_method_ids.insert(key.into(), value);
+                    if let Ok(fn_decl) = ctx.decl_engine.get_function(value.clone(), access_span) {
+                        impld_method_ids
+                            .insert((key, TyFunctionSig::from_fn_decl(&fn_decl)), value);
+                    }
                 }
             }
         }
 
         if errors.is_empty() {
-            let decl_mapping = DeclMapping::from_stub_and_impld_decl_ids_unique(
+            let decl_mapping = DeclMapping::from_stub_and_impld_decl_ids_with_function_sig(
                 original_method_ids,
                 impld_method_ids,
             );