Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/src/boost/libs/hana/example/tutorial/concepts.cpp b/src/boost/libs/hana/example/tutorial/concepts.cpp
new file mode 100644
index 000000000..751b47309
--- /dev/null
+++ b/src/boost/libs/hana/example/tutorial/concepts.cpp
@@ -0,0 +1,64 @@
+// Copyright Louis Dionne 2013-2017
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+
+#include <boost/hana/core/default.hpp>
+#include <boost/hana/core/tag_of.hpp>
+#include <boost/hana/integral_constant.hpp>
+
+#include <string>
+#include <type_traits>
+namespace hana = boost::hana;
+
+
+namespace with_special_base_class {
+//! [special_base_class]
+struct special_base_class { };
+
+template <typename T>
+struct print_impl : special_base_class {
+  template <typename ...Args>
+  static constexpr auto apply(Args&& ...) = delete;
+};
+
+template <typename T>
+struct Printable
+    : hana::integral_constant<bool,
+        !std::is_base_of<special_base_class, print_impl<hana::tag_of_t<T>>>::value
+    >
+{ };
+//! [special_base_class]
+
+//! [special_base_class_customize]
+struct Person { std::string name; };
+
+template <>
+struct print_impl<Person> /* don't inherit from special_base_class */ {
+  // ... implementation ...
+};
+
+static_assert(Printable<Person>::value, "");
+static_assert(!Printable<void>::value, "");
+//! [special_base_class_customize]
+}
+
+namespace actual {
+//! [actual]
+template <typename T>
+struct print_impl : hana::default_ {
+  template <typename ...Args>
+  static constexpr auto apply(Args&& ...) = delete;
+};
+
+template <typename T>
+struct Printable
+    : hana::integral_constant<bool,
+        !hana::is_default<print_impl<hana::tag_of_t<T>>>::value
+    >
+{ };
+//! [actual]
+
+static_assert(!Printable<void>::value, "");
+}
+
+int main() { }