From d0e5daf4412e90674866a09951457865c3fa8209 Mon Sep 17 00:00:00 2001
From: "Jordan Maples [MSFT]" <49793787+JordanMaples@users.noreply.github.com>
Date: Fri, 15 Nov 2019 12:11:44 -0800
Subject: [PATCH] fix ctad warning in llvm

---
 include/gsl/pointers                | 9 ++++++++-
 tests/no_exception_ensure_tests.cpp | 2 +-
 tests/no_exception_throw_tests.cpp  | 2 +-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/gsl/pointers b/include/gsl/pointers
index 7373826..2520f9e 100644
--- a/include/gsl/pointers
+++ b/include/gsl/pointers
@@ -100,7 +100,7 @@ public:
 
     constexpr operator T() const { return get(); }
     constexpr T operator->() const { return get(); }
-    constexpr decltype(auto) operator*() const { return *get(); } 
+    constexpr decltype(auto) operator*() const { return *get(); }
 
     // prevents compilation when someone attempts to assign a null pointer constant
     not_null(std::nullptr_t) = delete;
@@ -119,6 +119,13 @@ private:
     T ptr_;
 };
 
+#if (defined(__cplusplus) && (__cplusplus >= 201703L))
+// deduction guide to prevent the ctad-maybe-unsupported warning
+template <class T>
+not_null(T ptr) -> not_null<T>;
+
+#endif (defined(__cplusplus) && (__cplusplus >= 201703L))
+
 template <class T>
 auto make_not_null(T&& t) {
     return not_null<std::remove_cv_t<std::remove_reference_t<T>>>{std::forward<T>(t)};
diff --git a/tests/no_exception_ensure_tests.cpp b/tests/no_exception_ensure_tests.cpp
index b1ae15b..2ec0ebb 100644
--- a/tests/no_exception_ensure_tests.cpp
+++ b/tests/no_exception_ensure_tests.cpp
@@ -28,7 +28,7 @@ int operator_subscript_no_throw() noexcept
 
 void setup_termination_handler() noexcept
 {
-#if defined(_MSC_VER)
+#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)
 
     auto& handler = gsl::details::get_terminate_handler();
     handler = &test_terminate;
diff --git a/tests/no_exception_throw_tests.cpp b/tests/no_exception_throw_tests.cpp
index b28ad00..ddb6b07 100644
--- a/tests/no_exception_throw_tests.cpp
+++ b/tests/no_exception_throw_tests.cpp
@@ -28,7 +28,7 @@ int narrow_no_throw()
 
 void setup_termination_handler() noexcept
 {
-#if defined(_MSC_VER)
+#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)
 
     auto& handler = gsl::details::get_terminate_handler();
     handler = &test_terminate;