Replace _t<enable_if<...>> with enable_if_t<...>

Summary: Since we require C++14 in Folly and use `std::enable_if_t` in some places, there is no need for the `_t` workaround. Replace `_t<enable_if<...>>` with `enable_if_t<...>`. Reviewed By: yfeldblum Differential Revision: D13511564 fbshipit-source-id: 314b4a63281ce6b8275174ae89fab5fba1101bfb
facebook · Jan 8, 2019 · c3dd651 · c3dd651
1 parent f2074bf
commit c3dd651
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Showing 6 changed files with 27 additions and 31 deletions.
diff --git a/folly/ExceptionWrapper.h b/folly/ExceptionWrapper.h
@@ -52,7 +52,7 @@ FOLLY_GCC_DISABLE_NEW_SHADOW_WARNINGS
 namespace folly {
 
 #define FOLLY_REQUIRES_DEF(...) \
-  _t<std::enable_if<static_cast<bool>(__VA_ARGS__), long>>
+  std::enable_if_t<static_cast<bool>(__VA_ARGS__), long>
 
 #define FOLLY_REQUIRES(...) FOLLY_REQUIRES_DEF(__VA_ARGS__) = __LINE__
 

diff --git a/folly/Indestructible.h b/folly/Indestructible.h
@@ -80,21 +80,21 @@ class Indestructible final {
    */
   template <
       typename U = T,
-      _t<std::enable_if<std::is_constructible<T, U&&>::value>>* = nullptr,
-      _t<std::enable_if<
-          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>>* =
+      std::enable_if_t<std::is_constructible<T, U&&>::value>* = nullptr,
+      std::enable_if_t<
+          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>* =
           nullptr,
-      _t<std::enable_if<!std::is_convertible<U&&, T>::value>>* = nullptr>
+      std::enable_if_t<!std::is_convertible<U&&, T>::value>* = nullptr>
   explicit constexpr Indestructible(U&& u) noexcept(
       noexcept(T(std::declval<U>())))
       : storage_(std::forward<U>(u)) {}
   template <
       typename U = T,
-      _t<std::enable_if<std::is_constructible<T, U&&>::value>>* = nullptr,
-      _t<std::enable_if<
-          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>>* =
+      std::enable_if_t<std::is_constructible<T, U&&>::value>* = nullptr,
+      std::enable_if_t<
+          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>* =
           nullptr,
-      _t<std::enable_if<std::is_convertible<U&&, T>::value>>* = nullptr>
+      std::enable_if_t<std::is_convertible<U&&, T>::value>* = nullptr>
   /* implicit */ constexpr Indestructible(U&& u) noexcept(
       noexcept(T(std::declval<U>())))
       : storage_(std::forward<U>(u)) {}

diff --git a/folly/Memory.h b/folly/Memory.h
@@ -476,7 +476,7 @@ class AlignedSysAllocator : private Align {
   // TODO: remove this ctor, which is required only by gcc49
   template <
       typename S = Align,
-      _t<std::enable_if<std::is_default_constructible<S>::value, int>> = 0>
+      std::enable_if_t<std::is_default_constructible<S>::value, int> = 0>
   constexpr AlignedSysAllocator() noexcept(noexcept(Align())) : Align() {}
 
   template <typename U>

diff --git a/folly/ThreadLocal.h b/folly/ThreadLocal.h
@@ -60,9 +60,7 @@ class ThreadLocal {
  public:
   constexpr ThreadLocal() : constructor_([]() { return new T(); }) {}
 
-  template <
-      typename F,
-      _t<std::enable_if<is_invocable_r<T*, F>::value, int>> = 0>
+  template <typename F, std::enable_if_t<is_invocable_r<T*, F>::value, int> = 0>
   explicit ThreadLocal(F&& constructor)
       : constructor_(std::forward<F>(constructor)) {}
 

diff --git a/folly/lang/PropagateConst.h b/folly/lang/PropagateConst.h
@@ -69,39 +69,39 @@ class propagate_const {
 
   template <
       typename OtherPointer,
-      _t<std::enable_if<
+      std::enable_if_t<
           std::is_constructible<Pointer, OtherPointer&&>::value &&
               !std::is_convertible<OtherPointer&&, Pointer>::value,
-          int>> = 0>
+          int> = 0>
   constexpr explicit propagate_const(propagate_const<OtherPointer>&& other)
       : pointer_(static_cast<OtherPointer&&>(other.pointer_)) {}
 
   template <
       typename OtherPointer,
-      _t<std::enable_if<
+      std::enable_if_t<
           std::is_constructible<Pointer, OtherPointer&&>::value &&
               std::is_convertible<OtherPointer&&, Pointer>::value,
-          int>> = 0>
+          int> = 0>
   constexpr propagate_const(propagate_const<OtherPointer>&& other)
       : pointer_(static_cast<OtherPointer&&>(other.pointer_)) {}
 
   template <
       typename OtherPointer,
-      _t<std::enable_if<
+      std::enable_if_t<
           !detail::is_decay_propagate_const<OtherPointer>::value &&
               std::is_constructible<Pointer, OtherPointer&&>::value &&
               !std::is_convertible<OtherPointer&&, Pointer>::value,
-          int>> = 0>
+          int> = 0>
   constexpr explicit propagate_const(OtherPointer&& other)
       : pointer_(static_cast<OtherPointer&&>(other)) {}
 
   template <
       typename OtherPointer,
-      _t<std::enable_if<
+      std::enable_if_t<
           !detail::is_decay_propagate_const<OtherPointer>::value &&
               std::is_constructible<Pointer, OtherPointer&&>::value &&
               std::is_convertible<OtherPointer&&, Pointer>::value,
-          int>> = 0>
+          int> = 0>
   constexpr propagate_const(OtherPointer&& other)
       : pointer_(static_cast<OtherPointer&&>(other)) {}
 
@@ -119,9 +119,9 @@ class propagate_const {
 
   template <
       typename OtherPointer,
-      typename = _t<std::enable_if<
+      typename = std::enable_if_t<
           !detail::is_decay_propagate_const<OtherPointer>::value &&
-          std::is_convertible<OtherPointer&&, Pointer>::value>>>
+          std::is_convertible<OtherPointer&&, Pointer>::value>>
   FOLLY_CPP14_CONSTEXPR propagate_const& operator=(OtherPointer&& other) {
     pointer_ = static_cast<OtherPointer&&>(other);
     return *this;
@@ -164,18 +164,18 @@ class propagate_const {
 
   template <
       typename OtherPointer = Pointer,
-      typename = _t<std::enable_if<
+      typename = std::enable_if_t<
           std::is_pointer<OtherPointer>::value ||
-          std::is_convertible<OtherPointer, element_type*>::value>>>
+          std::is_convertible<OtherPointer, element_type*>::value>>
   FOLLY_CPP14_CONSTEXPR operator element_type*() {
     return get();
   }
 
   template <
       typename OtherPointer = Pointer,
-      typename = _t<std::enable_if<
+      typename = std::enable_if_t<
           std::is_pointer<OtherPointer>::value ||
-          std::is_convertible<OtherPointer, element_type const*>::value>>>
+          std::is_convertible<OtherPointer, element_type const*>::value>>
   constexpr operator element_type const*() const {
     return get();
   }

diff --git a/folly/stats/Histogram.h b/folly/stats/Histogram.h
@@ -472,15 +472,13 @@ class Histogram {
   };
 
  private:
-  template <
-      typename S,
-      typename = _t<std::enable_if<std::is_integral<S>::value>>>
+  template <typename S, typename = std::enable_if_t<std::is_integral<S>::value>>
   static constexpr _t<std::make_unsigned<S>> to_unsigned(S s) {
     return static_cast<_t<std::make_unsigned<S>>>(s);
   }
   template <
       typename S,
-      typename = _t<std::enable_if<!std::is_integral<S>::value>>>
+      typename = std::enable_if_t<!std::is_integral<S>::value>>
   static constexpr S to_unsigned(S s) {
     return s;
   }