Stop using ScopeGuardImpl in DynamicParser

[folly.git] / folly / Expected.h

diff --git a/folly/Expected.h b/folly/Expected.h
index c9874eba239531796a956a43afaed509bb784ee6..9d3535f9072320fbe28482b5a6d8e76235b366cc 100644 (file)
--- a/folly/Expected.h
+++ b/folly/Expected.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Facebook, Inc.
+ * Copyright 2017-present Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 /**
  * Like folly::Optional, but can store a value *or* an error.
  *
@@ -31,6 +30,8 @@
 
 #include <glog/logging.h>
 
+#include <folly/CPortability.h>
+#include <folly/CppAttributes.h>
 #include <folly/Likely.h>
 #include <folly/Optional.h>
 #include <folly/Portability.h>
@@ -38,6 +39,7 @@
 #include <folly/Traits.h>
 #include <folly/Unit.h>
 #include <folly/Utility.h>
+#include <folly/lang/ColdClass.h>
 
 #define FOLLY_EXPECTED_ID(X) FB_CONCATENATE(FB_CONCATENATE(Folly, X), __LINE__)
 
@@ -658,17 +660,23 @@ inline expected_detail::UnexpectedTag unexpected(
 /**
  * An exception type thrown by Expected on catastrophic logic errors.
  */
-class BadExpectedAccess : public std::logic_error {
+class FOLLY_EXPORT BadExpectedAccess : public std::logic_error {
  public:
   BadExpectedAccess() : std::logic_error("bad Expected access") {}
 };
 
+namespace expected_detail {
+
+[[noreturn]] void throwBadExpectedAccess();
+
+} // namespace expected_detail
+
 /**
  * Unexpected - a helper type used to disambiguate the construction of
  * Expected objects in the error state.
  */
 template <class Error>
-class Unexpected final {
+class Unexpected final : ColdClass {
   template <class E>
   friend class Unexpected;
   template <class V, class E>
@@ -681,7 +689,7 @@ class Unexpected final {
    * when the user tries to access the nested value but the Expected object is
    * actually storing an error code.
    */
-  class BadExpectedAccess : public folly::BadExpectedAccess {
+  class FOLLY_EXPORT BadExpectedAccess : public folly::BadExpectedAccess {
    public:
     explicit BadExpectedAccess(Error err)
         : folly::BadExpectedAccess{}, error_(std::move(err)) {}
@@ -1059,7 +1067,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
   void swap(Expected& that) noexcept(
       expected_detail::StrictAllOf<IsNothrowSwappable, Value, Error>::value) {
     if (this->uninitializedByException() || that.uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     using std::swap;
     if (*this) {
@@ -1100,11 +1108,11 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
    * Accessors
    */
   constexpr bool hasValue() const noexcept {
-    return expected_detail::Which::eValue == this->which_;
+    return LIKELY(expected_detail::Which::eValue == this->which_);
   }
 
   constexpr bool hasError() const noexcept {
-    return expected_detail::Which::eError == this->which_;
+    return UNLIKELY(expected_detail::Which::eError == this->which_);
   }
 
   using Base::uninitializedByException;
@@ -1199,7 +1207,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
           std::declval<const Base&>(),
           std::declval<Fns>()...)) {
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return expected_detail::ExpectedHelper::then_(
         base(), static_cast<Fns&&>(fns)...);
@@ -1210,7 +1218,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       std::declval<Base&>(),
       std::declval<Fns>()...)) {
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return expected_detail::ExpectedHelper::then_(
         base(), static_cast<Fns&&>(fns)...);
@@ -1221,7 +1229,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       std::declval<Base&&>(),
       std::declval<Fns>()...)) {
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return expected_detail::ExpectedHelper::then_(
         std::move(base()), static_cast<Fns&&>(fns)...);
@@ -1235,7 +1243,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       std::declval<Yes>()(std::declval<const Value&>())) {
     using Ret = decltype(std::declval<Yes>()(std::declval<const Value&>()));
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return Ret(expected_detail::ExpectedHelper::thenOrThrow_(
         base(), static_cast<Yes&&>(yes), static_cast<No&&>(no)));
@@ -1246,7 +1254,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       std::declval<Yes>()(std::declval<Value&>())) {
     using Ret = decltype(std::declval<Yes>()(std::declval<Value&>()));
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return Ret(expected_detail::ExpectedHelper::thenOrThrow_(
         base(), static_cast<Yes&&>(yes), static_cast<No&&>(no)));
@@ -1257,7 +1265,7 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       std::declval<Yes>()(std::declval<Value&&>())) {
     using Ret = decltype(std::declval<Yes>()(std::declval<Value&&>()));
     if (this->uninitializedByException()) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
     return Ret(expected_detail::ExpectedHelper::thenOrThrow_(
         std::move(base()), static_cast<Yes&&>(yes), static_cast<No&&>(no)));
@@ -1269,13 +1277,13 @@ class Expected final : expected_detail::ExpectedStorage<Value, Error> {
       if (LIKELY(hasError())) {
         throw typename Unexpected<Error>::BadExpectedAccess(this->error_);
       }
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
   }
 
   void requireError() const {
     if (UNLIKELY(!hasError())) {
-      throw BadExpectedAccess();
+      expected_detail::throwBadExpectedAccess();
     }
   }
 
@@ -1289,12 +1297,11 @@ inline typename std::enable_if<IsEqualityComparable<Value>::value, bool>::type
 operator==(
     const Expected<Value, Error>& lhs,
     const Expected<Value, Error>& rhs) {
-  if (UNLIKELY(lhs.which_ != rhs.which_)) {
-    return UNLIKELY(lhs.uninitializedByException()) ? false
-                                                    : throw BadExpectedAccess();
-  }
   if (UNLIKELY(lhs.uninitializedByException())) {
-    throw BadExpectedAccess();
+    expected_detail::throwBadExpectedAccess();
+  }
+  if (UNLIKELY(lhs.which_ != rhs.which_)) {
+    return false;
   }
   if (UNLIKELY(lhs.hasError())) {
     return true; // All error states are considered equal
@@ -1318,7 +1325,7 @@ operator<(
     const Expected<Value, Error>& rhs) {
   if (UNLIKELY(
           lhs.uninitializedByException() || rhs.uninitializedByException())) {
-    throw BadExpectedAccess();
+    expected_detail::throwBadExpectedAccess();
   }
   if (UNLIKELY(lhs.hasError())) {
     return !rhs.hasError();
@@ -1512,13 +1519,13 @@ expected_detail::Awaitable<Value, Error>
 }
 } // namespace folly
 
-// This makes folly::Optional<Value> useable as a coroutine return type..
-FOLLY_NAMESPACE_STD_BEGIN
+// This makes folly::Expected<Value> useable as a coroutine return type...
+namespace std {
 namespace experimental {
 template <typename Value, typename Error, typename... Args>
 struct coroutine_traits<folly::Expected<Value, Error>, Args...> {
   using promise_type = folly::expected_detail::Promise<Value, Error>;
 };
 } // namespace experimental
-FOLLY_NAMESPACE_STD_END
+} // namespace std
 #endif // FOLLY_HAS_COROUTINES