Merge topic 'optional'

197c5e12ad Source: Add cm::optional
170fcd715f Extend C++17 feature checks to require std::optional

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Sebastian Holtermann <sebholt@web.de>
Merge-request: !3644

1 files changed, 15 insertions, 1 deletions

diff --git a/bootstrap b/bootstrap
index eaccfc89c1..42503e3b42 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1147,6 +1147,20 @@ int check_cxx14()
 }
 #endif
 
+#if __cplusplus >= 201703L
+#include <optional>
+int check_cxx17()
+{
+  std::optional<int> oi = 0;
+  return oi.value();
+}
+#else
+int check_cxx17()
+{
+  return 0;
+}
+#endif
+
 class Class
 {
 public:
@@ -1157,7 +1171,7 @@ private:
 int main()
 {
   auto const c = std::unique_ptr<Class>(new Class);
-  std::cout << c->Get() << check_cxx14() << std::endl;
+  std::cout << c->Get() << check_cxx14() << check_cxx17() << std::endl;
   return 0;
 }
 ' > "${TMPFILE}.cxx"