compat: add function2 fwd decl

1 files changed, 35 insertions, 0 deletions

diff --git a/compat/function2.fwd.hpp b/compat/function2.fwd.hpp
new file mode 100644
index 00000000..ea0c0df9
--- /dev/null
+++ b/compat/function2.fwd.hpp
@@ -0,0 +1,35 @@
+#pragma once
+//  Copyright 2015-2020 Denis Blank <denis.blank at outlook dot com>
+//     Distributed under the Boost Software License, Version 1.0
+//       (See accompanying file LICENSE_1_0.txt or copy at
+//             http://www.boost.org/LICENSE_1_0.txt)
+
+namespace fu2 {
+inline namespace abi_400 {
+namespace detail {
+
+template <typename Config, typename Property> class function;
+template <bool Owning, bool Copyable, typename Capacity> struct config;
+template <bool Throws, bool HasStrongExceptGuarantee, typename... Args> struct property;
+
+} // namespace detail
+} // namespace abi_400
+
+struct capacity_default;
+
+template <bool IsOwning, bool IsCopyable, typename Capacity, bool IsThrowing,
+          bool HasStrongExceptGuarantee, typename... Signatures>
+using function_base = detail::function<
+    detail::config<IsOwning, IsCopyable, Capacity>,
+    detail::property<IsThrowing, HasStrongExceptGuarantee, Signatures...>>;
+
+template <typename... Signatures>
+using function = function_base<true, true, capacity_default, true, false, Signatures...>;
+
+template <typename... Signatures>
+using unique_function = function_base<true, false, capacity_default, true, false, Signatures...>;
+
+template <typename... Signatures>
+using function_view = function_base<false, true, capacity_default, true, false, Signatures...>;
+
+} // namespace fu2