#124 fix compiler error when passing functions to each() or iter() wi…

…thout &

flecs.h

@@ -15477,13 +15477,14 @@ struct each_invoker : public invoker {
     // If the number of arguments in the function signature is one more than the
     // number of components in the query, an extra entity arg is required.
     static constexpr bool PassEntity = 
-        sizeof...(Components) == (arity<Func>::value - 1);
+        sizeof...(Components) == (arity<decay_t<Func>>::value - 1);
 
     static_assert(arity<Func>::value > 0, 
         "each() must have at least one argument");
 
     using Terms = typename term_ptrs<Components ...>::array;
 
+    template < if_not_t< is_same< void(Func), void(Func)& >::value > = 0>
     explicit each_invoker(Func&& func) noexcept 
         : m_func(std::move(func)) { }
 
@@ -15586,6 +15587,7 @@ struct iter_invoker : invoker {
     using Terms = typename term_ptrs<Components ...>::array;
 
 public:
+    template < if_not_t< is_same< void(Func), void(Func)& >::value > = 0>
     explicit iter_invoker(Func&& func) noexcept 
         : m_func(std::move(func)) { }
 

include/flecs/addons/cpp/invoker.hpp

@@ -130,13 +130,14 @@ struct each_invoker : public invoker {
     // If the number of arguments in the function signature is one more than the
     // number of components in the query, an extra entity arg is required.
     static constexpr bool PassEntity = 
-        sizeof...(Components) == (arity<Func>::value - 1);
+        sizeof...(Components) == (arity<decay_t<Func>>::value - 1);
 
     static_assert(arity<Func>::value > 0, 
         "each() must have at least one argument");
 
     using Terms = typename term_ptrs<Components ...>::array;
 
+    template < if_not_t< is_same< void(Func), void(Func)& >::value > = 0>
     explicit each_invoker(Func&& func) noexcept 
         : m_func(std::move(func)) { }
 
@@ -239,6 +240,7 @@ struct iter_invoker : invoker {
     using Terms = typename term_ptrs<Components ...>::array;
 
 public:
+    template < if_not_t< is_same< void(Func), void(Func)& >::value > = 0>
     explicit iter_invoker(Func&& func) noexcept 
         : m_func(std::move(func)) { }
 

test/cpp_api/project.json

@@ -432,7 +432,11 @@
                 "un_instanced_query_w_singleton_iter",
                 "un_instanced_query_w_base_iter",
                 "query_each_from_component",
-                "query_iter_from_component"
+                "query_iter_from_component",
+                "query_each_w_func_ptr",
+                "query_iter_w_func_ptr",
+                "query_each_w_func_no_ptr",
+                "query_iter_w_func_no_ptr"
             ]
         }, {
             "id": "QueryBuilder",

test/cpp_api/src/Query.cpp

@@ -1716,3 +1716,82 @@ void Query_query_iter_from_component() {
     });
     test_int(count, 2);
 }
+
+static int invoked_count = 0;
+
+void EachFunc(flecs::entity e, Position& p) {
+    invoked_count ++;
+    p.x ++;
+    p.y ++;
+}
+
+void IterFunc(flecs::iter& it, Position* p) {
+    test_int(it.count(), 1);
+    invoked_count ++;
+    p->x ++;
+    p->y ++;
+}
+
+void Query_query_each_w_func_ptr() {
+    flecs::world w;
+
+    auto e = w.entity().set<Position>({10, 20});
+
+    auto q = w.query<Position>();
+
+    q.each(&EachFunc);
+
+    test_int(invoked_count, 1);
+
+    const Position *ptr = e.get<Position>();
+    test_int(ptr->x, 11);
+    test_int(ptr->y, 21);
+}
+
+void Query_query_iter_w_func_ptr() {
+    flecs::world w;
+
+    auto e = w.entity().set<Position>({10, 20});
+
+    auto q = w.query<Position>();
+
+    q.iter(&IterFunc);
+
+    test_int(invoked_count, 1);
+
+    const Position *ptr = e.get<Position>();
+    test_int(ptr->x, 11);
+    test_int(ptr->y, 21);
+}
+
+void Query_query_each_w_func_no_ptr() {
+    flecs::world w;
+
+    auto e = w.entity().set<Position>({10, 20});
+
+    auto q = w.query<Position>();
+
+    q.each(EachFunc);
+
+    test_int(invoked_count, 1);
+
+    const Position *ptr = e.get<Position>();
+    test_int(ptr->x, 11);
+    test_int(ptr->y, 21);
+}
+
+void Query_query_iter_w_func_no_ptr() {
+    flecs::world w;
+
+    auto e = w.entity().set<Position>({10, 20});
+
+    auto q = w.query<Position>();
+
+    q.iter(IterFunc);
+
+    test_int(invoked_count, 1);
+
+    const Position *ptr = e.get<Position>();
+    test_int(ptr->x, 11);
+    test_int(ptr->y, 21);
+}

test/cpp_api/src/main.cpp

@@ -409,6 +409,10 @@ void Query_un_instanced_query_w_singleton_iter(void);
 void Query_un_instanced_query_w_base_iter(void);
 void Query_query_each_from_component(void);
 void Query_query_iter_from_component(void);
+void Query_query_each_w_func_ptr(void);
+void Query_query_iter_w_func_ptr(void);
+void Query_query_each_w_func_no_ptr(void);
+void Query_query_iter_w_func_no_ptr(void);
 
 // Testsuite 'QueryBuilder'
 void QueryBuilder_builder_assign_same_type(void);
@@ -2327,6 +2331,22 @@ bake_test_case Query_testcases[] = {
     {
         "query_iter_from_component",
         Query_query_iter_from_component
+    },
+    {
+        "query_each_w_func_ptr",
+        Query_query_each_w_func_ptr
+    },
+    {
+        "query_iter_w_func_ptr",
+        Query_query_iter_w_func_ptr
+    },
+    {
+        "query_each_w_func_no_ptr",
+        Query_query_each_w_func_no_ptr
+    },
+    {
+        "query_iter_w_func_no_ptr",
+        Query_query_iter_w_func_no_ptr
     }
 };
 
@@ -3772,7 +3792,7 @@ static bake_test_suite suites[] = {
         "Query",
         NULL,
         NULL,
-        56,
+        60,
         Query_testcases
     },
     {