[shared_func] support free funcs

Author: iboB

include/itlib/shared_func.hpp

@@ -123,7 +123,7 @@ class shared_func<R(Args...)> {
     template <typename FO>
     struct wrapper : public wrapper_base {
         FO func_object;
-        wrapper(FO&& f) : func_object(std::forward<FO>(f)) {
+        wrapper(FO f) : func_object(std::move(f)) {
             this->func = +[](void* obj, Args&&... args) -> R {
                 return static_cast<wrapper*>(obj)->func_object(std::forward<Args>(args)...);
             };
@@ -144,7 +144,7 @@ class shared_func<R(Args...)> {
         if (!f) {
             return {};
         }
-        return std::make_shared<wrapper<FP>>(f);
+        return std::make_shared<wrapper<FP*>>(f);
     }
 };
 

test/t-shared_func-11.cpp

@@ -55,3 +55,14 @@ TEST_CASE("lambda") {
         CHECK(func.use_count() == 2);
     }
 }
+
+int sum(int a, int b) { return a + b; }
+
+TEST_CASE("free func") {
+    itlib::shared_func<int(int, int)> func = sum;
+    CHECK(func(1, 2) == 3);
+    func = [](int a, int b) { return a * b; };
+    CHECK(func(3, 4) == 12);
+    func = sum;
+    CHECK(func(3, 4) == 7);
+}