From b22fca578024ec5e09750209806a9b75e80932b7 Mon Sep 17 00:00:00 2001
From: Esteve Fernandez <esteve@osrfoundation.org>
Date: Fri, 11 Dec 2015 12:55:41 -0800
Subject: [PATCH] Add support for std::bind

---
 rclcpp/include/rclcpp/function_traits.hpp | 15 ++++++++++++
 rclcpp/test/test_function_traits.cpp      | 29 +++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/rclcpp/include/rclcpp/function_traits.hpp b/rclcpp/include/rclcpp/function_traits.hpp
index 5e3b498..910c353 100644
--- a/rclcpp/include/rclcpp/function_traits.hpp
+++ b/rclcpp/include/rclcpp/function_traits.hpp
@@ -15,6 +15,7 @@
 #ifndef RCLCPP__FUNCTION_TRAITS_HPP_
 #define RCLCPP__FUNCTION_TRAITS_HPP_
 
+#include <functional>
 #include <memory>
 #include <tuple>
 
@@ -77,6 +78,20 @@ template<typename ReturnTypeT, typename ... Args>
 struct function_traits<ReturnTypeT (*)(Args ...)>: function_traits<ReturnTypeT(Args ...)>
 {};
 
+// std::bind
+template<typename ClassT, typename ReturnTypeT, typename ... Args, typename ... FArgs>
+#if defined _LIBCPP_VERSION  // libc++ (Clang)
+struct function_traits<std::__1::__bind<ReturnTypeT (ClassT::*)(Args ...), FArgs ...>>
+#elif defined __GLIBCXX__  // glibc++ (GNU C++)
+struct function_traits<std::_Bind<std::_Mem_fn<ReturnTypeT (ClassT::*)(Args ...)>(FArgs ...)>>
+#elif defined _MSC_VER  // MS Visual Studio
+struct function_traits<
+  std::_Binder<std::_Unforced, ReturnTypeT(__cdecl ClassT::*)(Args ...), FArgs ...>
+>
+#endif
+  : function_traits<ReturnTypeT(Args ...)>
+{};
+
 // Lambdas
 template<typename ClassT, typename ReturnTypeT, typename ... Args>
 struct function_traits<ReturnTypeT (ClassT::*)(Args ...) const>
diff --git a/rclcpp/test/test_function_traits.cpp b/rclcpp/test/test_function_traits.cpp
index 363e9d1..aaaf53f 100644
--- a/rclcpp/test/test_function_traits.cpp
+++ b/rclcpp/test/test_function_traits.cpp
@@ -14,6 +14,7 @@
 
 #include <gtest/gtest.h>
 
+#include <functional>
 #include <string>
 
 #include "rclcpp/function_traits.hpp"
@@ -71,6 +72,15 @@ struct FunctionObjectOneIntOneChar
   }
 };
 
+struct ObjectMember
+{
+  int callback(bool a)
+  {
+    (void)a;
+    return 7;
+  }
+};
+
 template<
   typename FunctorT,
   std::size_t Arity = 0,
@@ -358,6 +368,16 @@ TEST(TestFunctionTraits, argument_types) {
         FunctionObjectOneIntOneChar
       >::template argument_type<1>
     >::value, "Functor accepts a char as second argument");
+
+  ObjectMember object_member;
+
+  auto bind_one_bool = std::bind(&ObjectMember::callback, &object_member, std::placeholders::_1);
+
+  static_assert(
+    std::is_same<
+      bool,
+      rclcpp::function_traits::function_traits<decltype(bind_one_bool)>::template argument_type<0>
+    >::value, "Functor accepts a bool as first argument");
 }
 
 /*
@@ -439,6 +459,15 @@ TEST(TestFunctionTraits, check_arguments) {
   static_assert(
     rclcpp::function_traits::check_arguments<FunctionObjectOneIntOneChar, int, char>::value,
     "Functor accepts an int and a char as arguments");
+
+  ObjectMember object_member;
+
+  auto bind_one_bool = std::bind(&ObjectMember::callback, &object_member, std::placeholders::_1);
+
+  // Test std::bind functions
+  static_assert(
+    rclcpp::function_traits::check_arguments<decltype(bind_one_bool), bool>::value,
+    "Functor accepts a single bool as arguments");
 }
 
 /*