From 9df8d1be3993a28bb78e8e0b3f8552ee57416a7f Mon Sep 17 00:00:00 2001
From: Simon Brand <simon@codeplay.com>
Date: Tue, 14 Aug 2018 09:56:31 +0100
Subject: [PATCH] Support std::vector of non-copyable types

---
 tests/constructors.cpp | 12 ++++++++++++
 tl/optional.hpp        | 20 ++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/tests/constructors.cpp b/tests/constructors.cpp
index a9a9c44..fc87a97 100644
--- a/tests/constructors.cpp
+++ b/tests/constructors.cpp
@@ -1,5 +1,12 @@
 #include "catch.hpp"
 #include "optional.hpp"
+#include <vector>
+
+struct foo {
+  foo() = default;
+  foo(foo&) = delete;
+  foo(foo&&) {};
+};
 
 TEST_CASE("Constructors", "[constructors]") {
   tl::optional<int> o1;
@@ -47,4 +54,9 @@ TEST_CASE("Constructors", "[constructors]") {
     REQUIRE(oo);
     REQUIRE(*oo == 42);
   }
+
+  std::vector<foo> v;
+  v.emplace_back();
+  tl::optional<std::vector<foo>> ov = std::move(v);
+  REQUIRE(ov->size() == 1);
 }
diff --git a/tl/optional.hpp b/tl/optional.hpp
index 0615901..c60c358 100644
--- a/tl/optional.hpp
+++ b/tl/optional.hpp
@@ -55,6 +55,26 @@
 
 // This one will be different for GCC 5.7 if it's ever supported
 #define TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>::value
+
+// GCC 5 < v < 8 has a bug in is_trivially_copy_constructible which breaks std::vector
+// for non-copyable types
+#elif (defined(__GNUC__) && __GNUC__ < 8 &&                                                \
+     !defined(__clang__))
+namespace tl {
+  namespace detail {
+      template<class T>
+      struct is_trivially_copy_constructible : std::is_trivially_copy_constructible<T>{};
+      template<class T, class A>
+      struct is_trivially_copy_constructible<std::vector<T,A>>
+          : std::is_trivially_copy_constructible<T>{};
+  }
+}
+
+#define TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)                                     \
+    tl::detail::is_trivially_copy_constructible<T>::value
+#define TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T)                                        \
+  std::is_trivially_copy_assignable<T>::value
+#define TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>::value
 #else
 #define TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)                                     \
   std::is_trivially_copy_constructible<T>::value