From edfdf3e6894a960351421ef978c9e1b0654006b2 Mon Sep 17 00:00:00 2001
From: Simon Brand <tartanllama@gmail.com>
Date: Mon, 25 Feb 2019 11:51:54 +0000
Subject: [PATCH] Move error inside and_then Fixes #49

---
 tests/issues.cpp | 21 ++++++++++++++++++++-
 tl/expected.hpp  |  8 ++++----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/tests/issues.cpp b/tests/issues.cpp
index b271140..9aa84ad 100644
--- a/tests/issues.cpp
+++ b/tests/issues.cpp
@@ -105,4 +105,23 @@ TEST_CASE("Issue 42", "[issues.42]") {
 TEST_CASE("Issue 43", "[issues.43]") {
 	auto result = tl::expected<void, std::string>{};
 	result = tl::make_unexpected(std::string{ "foo" });
-}
\ No newline at end of file
+}
+
+#include <memory>
+
+  using MaybeDataPtr = tl::expected<int, std::unique_ptr<int>>;
+
+  MaybeDataPtr test(int i) noexcept
+  {
+    return std::move(i);
+  }
+
+  MaybeDataPtr test2(int i) noexcept
+  {
+    return std::move(i);
+  }
+
+TEST_CASE("Issue 49", "[issues.49]") {
+  auto m = test(10)
+    .and_then(test2);
+}
diff --git a/tl/expected.hpp b/tl/expected.hpp
index e16058d..2042c51 100644
--- a/tl/expected.hpp
+++ b/tl/expected.hpp
@@ -1910,7 +1910,7 @@ constexpr auto and_then_impl(Exp &&exp, F &&f) {
 
   return exp.has_value()
              ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp))
-             : Ret(unexpect, exp.error());
+             : Ret(unexpect, std::forward<Exp>(exp).error());
 }
 
 template <class Exp, class F,
@@ -1920,7 +1920,7 @@ constexpr auto and_then_impl(Exp &&exp, F &&f) {
   static_assert(detail::is_expected<Ret>::value, "F must return an expected");
 
   return exp.has_value() ? detail::invoke(std::forward<F>(f))
-                         : Ret(unexpect, exp.error());
+                         : Ret(unexpect, std::forward<Exp>(exp).error());
 }
 #else
 template <class> struct TC;
@@ -1933,7 +1933,7 @@ auto and_then_impl(Exp &&exp, F &&f) -> Ret {
 
   return exp.has_value()
              ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp))
-             : Ret(unexpect, exp.error());
+             : Ret(unexpect, std::forward<Exp>(exp).error());
 }
 
 template <class Exp, class F,
@@ -1943,7 +1943,7 @@ constexpr auto and_then_impl(Exp &&exp, F &&f) -> Ret {
   static_assert(detail::is_expected<Ret>::value, "F must return an expected");
 
   return exp.has_value() ? detail::invoke(std::forward<F>(f))
-                         : Ret(unexpect, exp.error());
+                         : Ret(unexpect, std::forward<Exp>(exp).error());
 }
 #endif