Mark constructing an Unexpected as cold

[folly.git] / folly / Expected.h

diff --git a/folly/Expected.h b/folly/Expected.h
index 945797bc5e409252de708e727af14104188ebd4b..2705f33533e7e95fc43b191b9611f74e9f9f422e 100644 (file)
--- a/folly/Expected.h
+++ b/folly/Expected.h
@@ -31,6 +31,7 @@
 
 #include <glog/logging.h>
 
+#include <folly/CppAttributes.h>
 #include <folly/Likely.h>
 #include <folly/Optional.h>
 #include <folly/Portability.h>
@@ -711,8 +712,10 @@ class Unexpected final {
   Unexpected(Unexpected&&) = default;
   Unexpected& operator=(const Unexpected&) = default;
   Unexpected& operator=(Unexpected&&) = default;
-  constexpr /* implicit */ Unexpected(const Error& err) : error_(err) {}
-  constexpr /* implicit */ Unexpected(Error&& err) : error_(std::move(err)) {}
+  FOLLY_COLD constexpr /* implicit */ Unexpected(const Error& err)
+      : error_(err) {}
+  FOLLY_COLD constexpr /* implicit */ Unexpected(Error&& err)
+      : error_(std::move(err)) {}
 
   template <class Other FOLLY_REQUIRES_TRAILING(
       std::is_constructible<Error, Other&&>::value)>
@@ -1106,11 +1109,11 @@ 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;