From 129a7256a95a13f8087d42445e081c196e7c84a3 Mon Sep 17 00:00:00 2001
From: Jason Rhinelander <jason@imaginary.ca>
Date: Sun, 26 Mar 2017 00:01:52 -0300
Subject: [PATCH] Add and use detail::remove_reference_t

Adds `remove_reference_t` and converts various `typename
std::remove_reference<...>::type` to using it.
---
 include/pybind11/cast.h     | 4 ++--
 include/pybind11/common.h   | 2 ++
 include/pybind11/eigen.h    | 2 +-
 include/pybind11/pybind11.h | 6 +++---
 include/pybind11/pytypes.h  | 2 +-
 5 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index c997b90c0..180f48d2a 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -390,7 +390,7 @@ protected:
  */
 template <typename T>
 using cast_op_type =
-    conditional_t<std::is_pointer<typename std::remove_reference<T>::type>::value,
+    conditional_t<std::is_pointer<remove_reference_t<T>>::value,
         typename std::add_pointer<intrinsic_t<T>>::type,
         typename std::add_lvalue_reference<intrinsic_t<T>>::type>;
 
@@ -883,7 +883,7 @@ public:
     }
 
     static PYBIND11_DESCR name() { return type_descr(_(PYBIND11_STRING_NAME)); }
-    template <typename _T> using cast_op_type = typename std::remove_reference<pybind11::detail::cast_op_type<_T>>::type;
+    template <typename _T> using cast_op_type = remove_reference_t<pybind11::detail::cast_op_type<_T>>;
 };
 
 template <typename T1, typename T2> class type_caster<std::pair<T1, T2>> {
diff --git a/include/pybind11/common.h b/include/pybind11/common.h
index baa84b2c5..8d04c29bc 100644
--- a/include/pybind11/common.h
+++ b/include/pybind11/common.h
@@ -348,10 +348,12 @@ inline internals &get_internals();
 using std::enable_if_t;
 using std::conditional_t;
 using std::remove_cv_t;
+using std::remove_reference_t;
 #else
 template <bool B, typename T = void> using enable_if_t = typename std::enable_if<B, T>::type;
 template <bool B, typename T, typename F> using conditional_t = typename std::conditional<B, T, F>::type;
 template <typename T> using remove_cv_t = typename std::remove_cv<T>::type;
+template <typename T> using remove_reference_t = typename std::remove_reference<T>::type;
 #endif
 
 /// Index sequences
diff --git a/include/pybind11/eigen.h b/include/pybind11/eigen.h
index 8ceb94101..53d4dab08 100644
--- a/include/pybind11/eigen.h
+++ b/include/pybind11/eigen.h
@@ -542,7 +542,7 @@ public:
 template<typename Type>
 struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
     typedef typename Type::Scalar Scalar;
-    typedef typename std::remove_reference<decltype(*std::declval<Type>().outerIndexPtr())>::type StorageIndex;
+    typedef remove_reference_t<decltype(*std::declval<Type>().outerIndexPtr())> StorageIndex;
     typedef typename Type::Index Index;
     static constexpr bool rowMajor = Type::IsRowMajor;
 
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 21d911cdf..4954dcf4d 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -56,12 +56,12 @@ public:
     /// Construct a cpp_function from a lambda function (possibly with internal state)
     template <typename Func, typename... Extra, typename = detail::enable_if_t<
         detail::satisfies_none_of<
-            typename std::remove_reference<Func>::type,
+            detail::remove_reference_t<Func>,
             std::is_function, std::is_pointer, std::is_member_pointer
         >::value>
     >
     cpp_function(Func &&f, const Extra&... extra) {
-        using FuncType = typename detail::remove_class<decltype(&std::remove_reference<Func>::type::operator())>::type;
+        using FuncType = typename detail::remove_class<decltype(&detail::remove_reference_t<Func>::operator())>::type;
         initialize(std::forward<Func>(f),
                    (FuncType *) nullptr, extra...);
     }
@@ -93,7 +93,7 @@ protected:
     template <typename Func, typename Return, typename... Args, typename... Extra>
     void initialize(Func &&f, Return (*)(Args...), const Extra&... extra) {
 
-        struct capture { typename std::remove_reference<Func>::type f; };
+        struct capture { detail::remove_reference_t<Func> f; };
 
         /* Store the function including any extra state it might have (e.g. a lambda capture object) */
         auto rec = make_function_record();
diff --git a/include/pybind11/pytypes.h b/include/pybind11/pytypes.h
index 8a8499c13..b186c0b3f 100644
--- a/include/pybind11/pytypes.h
+++ b/include/pybind11/pytypes.h
@@ -44,7 +44,7 @@ using tuple_accessor = accessor<accessor_policies::tuple_item>;
 
 /// Tag and check to identify a class which implements the Python object API
 class pyobject_tag { };
-template <typename T> using is_pyobject = std::is_base_of<pyobject_tag, typename std::remove_reference<T>::type>;
+template <typename T> using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
 
 /** \rst
     A mixin class which adds common functions to `handle`, `object` and various accessors.