Update on "Replace c10::guts::stuff with std::stuff"

Since we now have C++14, we don't need these c10::guts helpers anymore

- c10::guts::make_unique -> std::make_unique
- c10::guts::integer_sequence -> std::integer_sequence
- c10::guts::index_sequence -> std::index_sequence
- c10::guts::make_integer_sequence -> std::make_integer_sequence
- c10::guts::make_index_sequence -> std::make_index_sequence
- c10::guts::index_sequence_for -> std::index_sequence_for
- c10::guts::conditional_t -> std::conditional_t
- c10::guts::enable_if_t -> std::enable_if_t
- c10::guts::add_lvalue_reference_t -> std::add_lvalue_reference_t
- c10::guts::remove_reference_t -> std::remove_reference_t
- c10::guts::remove_cv_t -> std::remove_cv_t
- c10::guts::result_of_t -> std::result_of_t
- c10::guts::decay_t -> std::decay_t
- c10::guts::remove_const_t -> std::remove_const_t
- c10::guts::remove_pointer_t -> std::remove_pointer_t
- c10::guts::common_type_t -> std::common_type_t

Differential Revision: [D18869639](https://our.internmc.facebook.com/intern/diff/D18869639/)

[ghstack-poisoned]

Author: smessmer

c10/test/util/C++17_test.cpp

@@ -1,2 +1,14 @@
 #include <c10/util/C++17.h>
 
+using c10::guts::max;
+using c10::guts::min;
+
+static_assert(min(3, 5) == 3, "");
+static_assert(min(5, 3) == 3, "");
+static_assert(min(3, 3) == 3, "");
+static_assert(min(3.0, 3.1) == 3.0, "");
+
+static_assert(max(3, 5) == 5, "");
+static_assert(max(5, 3) == 5, "");
+static_assert(max(3, 3) == 3, "");
+static_assert(max(3.0, 3.1) == 3.1, "");

c10/util/C++17.h

@@ -189,6 +189,16 @@ template<class T> inline std::string to_string(T value) {
     return detail::to_string_<T>::call(value);
 }
 
+template <class T>
+constexpr const T& min(const T& a, const T& b) {
+  return (b < a) ? b : a;
+}
+
+template <class T>
+constexpr const T& max(const T& a, const T& b) {
+  return (a < b) ? b : a;
+}
+
 }}
 
 #endif // C10_UTIL_CPP17_H_

c10/util/string_view.h

@@ -180,7 +180,7 @@ class basic_string_view final {
           c10::guts::to_string(pos) +
           ", size: " + c10::guts::to_string(size()));
     }
-    size_type copy_length = std::min(count, size_ - pos);
+    size_type copy_length = guts::min(count, size_ - pos);
     for (auto iter = begin() + pos, end = iter + copy_length; iter != end;) {
       *(dest++) = *(iter++);
     }
@@ -205,7 +205,7 @@ class basic_string_view final {
   constexpr int compare(basic_string_view rhs) const noexcept {
 #if __cpp_constexpr >= 201304
     // if we are in C++14, write it iteratively. This is faster.
-    for (size_t i = 0, end = std::min(size(), rhs.size()); i < end; ++i) {
+    for (size_t i = 0, end = guts::min(size(), rhs.size()); i < end; ++i) {
       if (at_(i) < rhs.at_(i)) {
         return -1;
       } else if (at_(i) > rhs.at_(i)) {
@@ -378,7 +378,7 @@ class basic_string_view final {
     }
 
     if (v.size() <= size()) {
-      pos = std::min(size() - v.size(), pos);
+      pos = guts::min(size() - v.size(), pos);
       do {
         if (v.at_(0) == at_(pos) &&
             v.substr_(1).equals_(substr_(pos + 1, v.size() - 1))) {
@@ -524,7 +524,7 @@ class basic_string_view final {
 
   constexpr basic_string_view substr_(size_type pos = 0, size_type count = npos)
       const {
-    return basic_string_view{begin_ + pos, std::min(count, size() - pos)};
+    return basic_string_view{begin_ + pos, guts::min(count, size() - pos)};
   }
 
   template <class Condition>
@@ -556,7 +556,7 @@ class basic_string_view final {
 #if __cpp_constexpr >= 201304
     // if we are in C++14, write it iteratively. This is faster.
     if (size() > 0) {
-      pos = std::min(size() - 1, pos);
+      pos = guts::min(size() - 1, pos);
       do {
         if (condition(at_(pos))) {
           return pos;

caffe2/utils/threadpool/WorkersPool.h

@@ -231,7 +231,7 @@ class alignas(kGEMMLOWPCacheLineSize) Worker {
       : task_(nullptr),
         state_(State::ThreadStartup),
         counter_to_decrement_when_ready_(counter_to_decrement_when_ready) {
-    thread_ = make_unique<std::thread>([this]() { this->ThreadFunc(); });
+    thread_ = std::make_unique<std::thread>([this]() { this->ThreadFunc(); });
   }
 
   ~Worker() {