From 4aca266eb98c8d982d55bcd43b6f5b96cedfca6e Mon Sep 17 00:00:00 2001
From: Krylov Yaroslav <krylov.yaroslav@gmail.com>
Date: Sun, 2 Jul 2023 15:42:57 +0400
Subject: [PATCH] extract container related type traits into
 ureact/detail/container_type_traits.hpp

---
 include/ureact/adaptor/collect.hpp            | 28 +--------
 include/ureact/adaptor/join.hpp               | 10 +--
 .../ureact/detail/container_type_traits.hpp   | 63 +++++++++++++++++++
 3 files changed, 65 insertions(+), 36 deletions(-)
 create mode 100644 include/ureact/detail/container_type_traits.hpp

diff --git a/include/ureact/adaptor/collect.hpp b/include/ureact/adaptor/collect.hpp
index bbfbaddb..72b03d74 100644
--- a/include/ureact/adaptor/collect.hpp
+++ b/include/ureact/adaptor/collect.hpp
@@ -12,39 +12,13 @@
 
 #include <ureact/adaptor/fold.hpp>
 #include <ureact/detail/adaptor.hpp>
+#include <ureact/detail/container_type_traits.hpp>
 
 UREACT_BEGIN_NAMESPACE
 
 namespace detail
 {
 
-template <typename Cont, typename Value, typename = void>
-struct has_push_back_method : std::false_type
-{};
-
-template <typename Cont, class Value>
-struct has_push_back_method<Cont,
-    Value,
-    std::void_t<decltype( std::declval<Cont>().push_back( std::declval<Value>() ) )>>
-    : std::true_type
-{};
-
-template <typename Cont, class Value>
-inline constexpr bool has_push_back_method_v = has_push_back_method<Cont, Value>::value;
-
-template <typename Cont, typename Value, typename = void>
-struct has_insert_method : std::false_type
-{};
-
-template <typename Cont, class Value>
-struct has_insert_method<Cont,
-    Value,
-    std::void_t<decltype( std::declval<Cont>().insert( std::declval<Value>() ) )>> : std::true_type
-{};
-
-template <typename Cont, class Value>
-inline constexpr bool has_insert_method_v = has_insert_method<Cont, Value>::value;
-
 template <template <typename...> class ContT>
 struct CollectClosure : AdaptorClosure
 {
diff --git a/include/ureact/adaptor/join.hpp b/include/ureact/adaptor/join.hpp
index 529b0f64..bbf09850 100644
--- a/include/ureact/adaptor/join.hpp
+++ b/include/ureact/adaptor/join.hpp
@@ -11,21 +11,13 @@
 #define UREACT_ADAPTOR_JOIN_HPP
 
 #include <ureact/adaptor/process.hpp>
+#include <ureact/detail/container_type_traits.hpp>
 
 UREACT_BEGIN_NAMESPACE
 
 namespace detail
 {
 
-template <class ContainerT>
-struct container_value
-{
-    using type = std::decay_t<decltype( *std::begin( std::declval<ContainerT>() ) )>;
-};
-
-template <class ContainerT>
-using container_value_t = typename container_value<ContainerT>::type;
-
 struct JoinClosure : AdaptorClosure
 {
     /*!
diff --git a/include/ureact/detail/container_type_traits.hpp b/include/ureact/detail/container_type_traits.hpp
new file mode 100644
index 00000000..26513eb7
--- /dev/null
+++ b/include/ureact/detail/container_type_traits.hpp
@@ -0,0 +1,63 @@
+//
+//         Copyright (C) 2014-2017 Sebastian Jeckel.
+//         Copyright (C) 2020-2023 Krylov Yaroslav.
+//
+// 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)
+//
+
+#ifndef UREACT_DETAIL_CONTAINER_TYPE_TRAITS_HPP
+#define UREACT_DETAIL_CONTAINER_TYPE_TRAITS_HPP
+
+#include <type_traits>
+#include <vector> // for std::begin(). It is declared in core headers anyway
+
+#include <ureact/detail/defines.hpp>
+
+UREACT_BEGIN_NAMESPACE
+
+namespace detail
+{
+
+template <typename Cont, typename Value, typename = void>
+struct has_push_back_method : std::false_type
+{};
+
+template <typename Cont, class Value>
+struct has_push_back_method<Cont,
+    Value,
+    std::void_t<decltype( std::declval<Cont>().push_back( std::declval<Value>() ) )>>
+    : std::true_type
+{};
+
+template <typename Cont, class Value>
+inline constexpr bool has_push_back_method_v = has_push_back_method<Cont, Value>::value;
+
+template <typename Cont, typename Value, typename = void>
+struct has_insert_method : std::false_type
+{};
+
+template <typename Cont, class Value>
+struct has_insert_method<Cont,
+    Value,
+    std::void_t<decltype( std::declval<Cont>().insert( std::declval<Value>() ) )>> : std::true_type
+{};
+
+template <typename Cont, class Value>
+inline constexpr bool has_insert_method_v = has_insert_method<Cont, Value>::value;
+
+template <class ContainerT>
+struct container_value
+{
+    using type = std::decay_t<decltype( *std::begin( std::declval<ContainerT>() ) )>;
+};
+
+template <class ContainerT>
+using container_value_t = typename container_value<ContainerT>::type;
+
+} // namespace detail
+
+UREACT_END_NAMESPACE
+
+#endif //UREACT_DETAIL_CONTAINER_TYPE_TRAITS_HPP