From 4afdf8745a873a813cc8c7cee412a68666a03c9b Mon Sep 17 00:00:00 2001
From: Billy O'Neal <bion@microsoft.com>
Date: Tue, 31 Oct 2023 16:57:14 -0700
Subject: [PATCH] Apply conditional noexcept to Expected's constructors.
 (#1251)

---
 include/vcpkg/base/expected.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/vcpkg/base/expected.h b/include/vcpkg/base/expected.h
index 9ead2d49ed..49ced29d1c 100644
--- a/include/vcpkg/base/expected.h
+++ b/include/vcpkg/base/expected.h
@@ -74,7 +74,8 @@ namespace vcpkg
                  std::enable_if_t<std::is_convertible_v<ConvToT, T> &&
                                       !std::is_same_v<std::remove_reference_t<ConvToT>, Error>,
                                   int> = 0>
-        ExpectedT(ConvToT&& t) : m_t(std::forward<ConvToT>(t)), value_is_error(false)
+        ExpectedT(ConvToT&& t) noexcept(std::is_nothrow_constructible_v<T, ConvToT>)
+            : m_t(std::forward<ConvToT>(t)), value_is_error(false)
         {
         }
 
@@ -83,18 +84,21 @@ namespace vcpkg
                                       !std::is_same_v<std::remove_reference_t<ConvToError>, T>,
                                   int> = 0,
                  int = 1>
-        ExpectedT(ConvToError&& e) : m_error(std::forward<ConvToError>(e)), value_is_error(true)
+        ExpectedT(ConvToError&& e) noexcept(std::is_nothrow_constructible_v<Error, ConvToError>)
+            : m_error(std::forward<ConvToError>(e)), value_is_error(true)
         {
         }
 
         // Constructors that explicitly specify left or right exist if the parameter is convertible to T or Error
         template<class ConvToT, std::enable_if_t<std::is_convertible_v<ConvToT, T>, int> = 0>
-        ExpectedT(ConvToT&& t, ExpectedLeftTag) : m_t(std::forward<ConvToT>(t)), value_is_error(false)
+        ExpectedT(ConvToT&& t, ExpectedLeftTag) noexcept(std::is_nothrow_constructible_v<T, ConvToT>)
+            : m_t(std::forward<ConvToT>(t)), value_is_error(false)
         {
         }
 
         template<class ConvToError, std::enable_if_t<std::is_convertible_v<ConvToError, Error>, int> = 0>
-        ExpectedT(ConvToError&& e, ExpectedRightTag) : m_error(std::forward<ConvToError>(e)), value_is_error(true)
+        ExpectedT(ConvToError&& e, ExpectedRightTag) noexcept(std::is_nothrow_constructible_v<Error, ConvToError>)
+            : m_error(std::forward<ConvToError>(e)), value_is_error(true)
         {
         }