Implicitly add cast if implicit cast is found

src/typechecker.cpp

@@ -5,19 +5,24 @@
 #include "result.h"
 
 namespace {
-    enum class TypecheckRes {
+    enum class TypecheckResKind {
         Ok,
         Castable,
     };
 
+    struct TypecheckRes {
+        TypecheckResKind kind;
+        std::shared_ptr<types::Type> result;
+    };
+
     Result<TypecheckRes, std::string> check_type(typecheck::State& state, std::shared_ptr<types::Type> checked, std::shared_ptr<types::Type> target) {
         auto potential_cast = types::find_cast(state.casts, checked, target);
 
         if (types::types_equal(checked, target)) {
-            return TypecheckRes::Ok;
+            return TypecheckRes{ TypecheckResKind::Ok, target };
         }
         else if (potential_cast.has_value() && potential_cast->allow_implicit) {
-            return TypecheckRes::Castable;
+            return TypecheckRes{ TypecheckResKind::Castable, target };
         }
 
         return std::string{ "Types " + checked->formatted() + " and " + target->formatted() + " incompatible" };
@@ -29,12 +34,13 @@ namespace {
         typecheck::State& state) {
         if (res.ok()) {
             auto result = res.unwrap();
-            if (result == TypecheckRes::Ok) {
+            if (result.kind == TypecheckResKind::Ok) {
                 return expr;
             }
             else {
-                state.errors.push_back(CompileError("Casting not yet implemented", expr->m_meta));
+                return std::unique_ptr<AST::Expression> {
-                return expr;
+                    new AST::CastExpression{ expr->m_meta, result.result, std::move(expr) }
+                };
             }
         }
         else {