From fab9721430aa83ddb266aca029e270aec81c021d Mon Sep 17 00:00:00 2001
From: MarcoFalke <*~=`'#}+{/-|&$^_@721217.xyz>
Date: Tue, 9 Dec 2025 09:26:17 +0100
Subject: [PATCH] util: Implement Expected::value()&& and Expected::error()&&

They are currently unused, but implementing them is closer to the
std::expected.
---
 src/test/util_expected_tests.cpp | 21 +++++++++++++++++++++
 src/util/expected.h              | 18 ++++++------------
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/src/test/util_expected_tests.cpp b/src/test/util_expected_tests.cpp
index e626a9887c7..7c9d62ad392 100644
--- a/src/test/util_expected_tests.cpp
+++ b/src/test/util_expected_tests.cpp
@@ -43,6 +43,13 @@ BOOST_AUTO_TEST_CASE(expected_value)
     BOOST_CHECK_EQUAL(read->x, 45);
 }
 
+BOOST_AUTO_TEST_CASE(expected_value_rvalue)
+{
+    Expected<std::unique_ptr<int>, int> no_copy{std::make_unique<int>(5)};
+    const auto moved{std::move(no_copy).value()};
+    BOOST_CHECK_EQUAL(*moved, 5);
+}
+
 BOOST_AUTO_TEST_CASE(expected_value_or)
 {
     Expected<std::unique_ptr<int>, int> no_copy{std::make_unique<int>(1)};
@@ -81,6 +88,20 @@ BOOST_AUTO_TEST_CASE(expected_error)
     BOOST_CHECK_EQUAL(read.error(), "fail1");
 }
 
+BOOST_AUTO_TEST_CASE(expected_error_rvalue)
+{
+    {
+        Expected<int, std::unique_ptr<int>> nocopy_err{Unexpected{std::make_unique<int>(7)}};
+        const auto moved{std::move(nocopy_err).error()};
+        BOOST_CHECK_EQUAL(*moved, 7);
+    }
+    {
+        Expected<void, std::unique_ptr<int>> void_nocopy_err{Unexpected{std::make_unique<int>(9)}};
+        const auto moved{std::move(void_nocopy_err).error()};
+        BOOST_CHECK_EQUAL(*moved, 9);
+    }
+}
+
 BOOST_AUTO_TEST_CASE(unexpected_error_accessors)
 {
     Unexpected u{std::make_unique<int>(-1)};
diff --git a/src/util/expected.h b/src/util/expected.h
index a7d02c39dcc..85d4bf9d47a 100644
--- a/src/util/expected.h
+++ b/src/util/expected.h
@@ -57,20 +57,21 @@ public:
     constexpr bool has_value() const noexcept { return m_data.index() == 0; }
     constexpr explicit operator bool() const noexcept { return has_value(); }
 
-    constexpr const T& value() const LIFETIMEBOUND
+    constexpr const T& value() const& LIFETIMEBOUND
     {
         if (!has_value()) {
             throw BadExpectedAccess{};
         }
         return std::get<0>(m_data);
     }
-    constexpr T& value() LIFETIMEBOUND
+    constexpr T& value() & LIFETIMEBOUND
     {
         if (!has_value()) {
             throw BadExpectedAccess{};
         }
         return std::get<0>(m_data);
     }
+    constexpr T&& value() && LIFETIMEBOUND { return std::move(value()); }
 
     template <class U>
     T value_or(U&& default_value) const&
@@ -83,16 +84,9 @@ public:
         return has_value() ? std::move(value()) : std::forward<U>(default_value);
     }
 
-    constexpr const E& error() const LIFETIMEBOUND
-    {
-        assert(!has_value());
-        return std::get<1>(m_data);
-    }
-    constexpr E& error() LIFETIMEBOUND
-    {
-        assert(!has_value());
-        return std::get<1>(m_data);
-    }
+    constexpr const E& error() const& noexcept LIFETIMEBOUND { return *Assert(std::get_if<1>(&m_data)); }
+    constexpr E& error() & noexcept LIFETIMEBOUND { return *Assert(std::get_if<1>(&m_data)); }
+    constexpr E&& error() && noexcept LIFETIMEBOUND { return std::move(error()); }
 
     constexpr T& operator*() noexcept LIFETIMEBOUND { return value(); }
     constexpr const T& operator*() const noexcept LIFETIMEBOUND { return value(); }