Add support for using reference_wrapper with member pointers

boostorg · Jun 25, 2016 · bbdd63b · bbdd63b
1 parent cae0591
commit bbdd63b
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Showing 2 changed files with 48 additions and 0 deletions.
diff --git a/include/fit/apply.hpp b/include/fit/apply.hpp
@@ -167,6 +167,15 @@ struct apply_f
         apply_mem_fn()(f, *FIT_FORWARD(T)(obj), FIT_FORWARD(Ts)(xs)...)
     );
 
+    template<class F, class T, class... Ts, class=typename std::enable_if<(
+        std::is_member_function_pointer<typename std::decay<F>::type>::value
+    )>::type>
+    constexpr FIT_SFINAE_MANUAL_RESULT(apply_mem_fn, id_<F>, id_<T&>, id_<Ts>...) 
+    operator()(F&& f, const std::reference_wrapper<T>& ref, Ts&&... xs) const FIT_SFINAE_MANUAL_RETURNS
+    (
+        apply_mem_fn()(f, ref.get(), FIT_FORWARD(Ts)(xs)...)
+    );
+
     template<class F, class T, class=typename std::enable_if<(
         std::is_member_object_pointer<typename std::decay<F>::type>::value
     )>::type>
@@ -184,6 +193,15 @@ struct apply_f
     (
         apply_mem_data()(f, *FIT_FORWARD(T)(obj))
     );
+
+    template<class F, class T, class=typename std::enable_if<(
+        std::is_member_object_pointer<typename std::decay<F>::type>::value
+    )>::type>
+    constexpr FIT_SFINAE_MANUAL_RESULT(apply_mem_data, id_<F>, id_<T&>) 
+    operator()(F&& f, const std::reference_wrapper<T>& ref) const FIT_SFINAE_MANUAL_RETURNS
+    (
+        apply_mem_data()(f, ref.get())
+    );
 
 #else
 
@@ -194,6 +212,10 @@ struct apply_f
     template <class PMD, class Pointer>
     constexpr auto operator()(PMD&& pmd, Pointer&& ptr) const
     FIT_RETURNS((*FIT_FORWARD(Pointer)(ptr)).*FIT_FORWARD(PMD)(pmd));
+
+    template <class Base, class T, class Derived>
+    constexpr auto operator()(T Base::*pmd, const std::reference_wrapper<Derived>& ref) const
+    FIT_RETURNS(ref.get().*pmd);
 
     template <class Base, class T, class Derived, class... Args>
     constexpr auto operator()(T Base::*pmf, Derived&& ref, Args&&... args) const
@@ -203,6 +225,10 @@ struct apply_f
     constexpr auto operator()(PMF&& pmf, Pointer&& ptr, Args&&... args) const
     FIT_RETURNS(((*FIT_FORWARD(Pointer)(ptr)).*FIT_FORWARD(PMF)(pmf))(FIT_FORWARD(Args)(args)...));
 
+    template <class Base, class T, class Derived, class... Args>
+    constexpr auto operator()(T Base::*pmf, const std::reference_wrapper<Derived>& ref, Args&&... args) const
+    FIT_RETURNS((ref.get().*pmf)(FIT_FORWARD(Args)(args)...));
+
 #endif
     template<class F, class... Ts>
     constexpr FIT_SFINAE_RESULT(F, id_<Ts>...) 

diff --git a/test/apply.cpp b/test/apply.cpp
@@ -373,3 +373,25 @@ FIT_TEST_CASE()
     FIT_TEST_CHECK( fit::apply( &dm_t::m, pcx ) == 603 );
 
 }
+
+
+struct X_ref
+{
+    int f()
+    {
+        return 1;
+    }
+
+    int g() const
+    {
+        return 2;
+    }
+};
+
+FIT_TEST_CASE()
+{
+    X_ref x;
+
+    FIT_TEST_CHECK( fit::apply( &X_ref::f, std::ref( x ) ) == 1 );
+    FIT_TEST_CHECK( fit::apply( &X_ref::g, std::cref( x ) ) == 2 );
+}