From e17a92f2a89369100ce45784516bacc2622167af Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Thu, 13 Dec 2018 16:43:17 -0800
Subject: [PATCH] Workarounds for msvc-14

---
 CHANGELOG.md                                  |  6 ++
 Jamfile                                       |  3 +-
 .../boost/beast/core/detail/buffers_pair.hpp  | 75 ++++++++++++-------
 include/boost/beast/core/detail/tuple.hpp     | 33 +++++++-
 .../boost/beast/core/impl/multi_buffer.hpp    | 24 ++++++
 .../boost/beast/core/impl/static_buffer.hpp   | 68 ++++++++---------
 test/beast/core/multi_buffer.cpp              |  3 +-
 7 files changed, 146 insertions(+), 66 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 738474ff..62eba45c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+Version 199:
+
+* Workarounds for msvc-14
+
+--------------------------------------------------------------------------------
+
 Version 198:
 
 * flat_buffer improvements
diff --git a/Jamfile b/Jamfile
index 6ec99363..db60ae95 100644
--- a/Jamfile
+++ b/Jamfile
@@ -103,7 +103,8 @@ project /boost/beast
     <define>BOOST_ASIO_DISABLE_BOOST_DATE_TIME=1
     <define>BOOST_ASIO_DISABLE_BOOST_REGEX=1
     <define>BOOST_COROUTINES_NO_DEPRECATION_WARNING=1
-    <toolset>msvc:<cxxflags>"/bigobj /permissive-"
+    <toolset>msvc:<cxxflags>"/bigobj"
+    <toolset>msvc-14.1:<cxxflags>"/permissive-"
     <toolset>msvc:<define>_SCL_SECURE_NO_WARNINGS=1
     <toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS=1
     <toolset>msvc:<define>_SILENCE_CXX17_ALLOCATOR_VOID_DEPRECATION_WARNING
diff --git a/include/boost/beast/core/detail/buffers_pair.hpp b/include/boost/beast/core/detail/buffers_pair.hpp
index 7a77aaa5..8b557cd8 100644
--- a/include/boost/beast/core/detail/buffers_pair.hpp
+++ b/include/boost/beast/core/detail/buffers_pair.hpp
@@ -12,58 +12,76 @@
 
 #include <boost/asio/buffer.hpp>
 #include <boost/assert.hpp>
+#include <boost/config/workaround.hpp>
 #include <type_traits>
 
 namespace boost {
 namespace beast {
 namespace detail {
 
-template<bool IsMutable>
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
+# pragma warning (push)
+# pragma warning (disable: 4521) // multiple copy constructors specified
+# pragma warning (disable: 4522) // multiple assignment operators specified
+#endif
+
+template<bool isMutable>
 class buffers_pair
 {
-    template<bool IsMutable_>
-    friend class buffers_pair;
-
 public:
     // VFALCO: This type is public otherwise
     //         asio::buffers_iterator won't compile.
     using value_type = typename
-        std::conditional<IsMutable,
+        std::conditional<isMutable,
             net::mutable_buffer,
             net::const_buffer>::type;
 
     using const_iterator = value_type const*;
 
     buffers_pair() = default;
-    buffers_pair(buffers_pair const&) = default;
-    buffers_pair& operator=(buffers_pair const&) = default;
-
-    template<
-        bool IsMutable_ = IsMutable,
-        class = typename
-            std::enable_if<! IsMutable_>::type>
-    buffers_pair(
-        buffers_pair<true> const& other) noexcept
-        : b_{other.b_[0], other.b_[1]}
+#if defined(BOOST_MSVC) && BOOST_MSVC < 1910
+    buffers_pair(buffers_pair const& other)
+        : buffers_pair(
+            *other.begin(), *(other.begin() + 1))
     {
     }
 
-    template<
-        bool IsMutable_ = IsMutable,
-        class = typename
-        std::enable_if<! IsMutable_>::type>
-    buffers_pair& operator=(
-        buffers_pair<true> const& other) noexcept
+    buffers_pair&
+    operator=(buffers_pair const& other)
     {
-        b_ = {other.b_[0], other.b_[1]};
+        b_[0] = *other.begin();
+        b_[1] = *(other.begin() + 1);
         return *this;
     }
+#else
+    buffers_pair(buffers_pair const& other) = default;
+    buffers_pair& operator=(buffers_pair const& other) = default;
+#endif
 
-    value_type&
-    operator[](int i) noexcept
+    template<
+        bool isMutable_ = isMutable,
+        class = typename std::enable_if<
+            ! isMutable_>::type>
+    buffers_pair(buffers_pair<true> const& other)
+        : buffers_pair(
+            *other.begin(), *(other.begin() + 1))
+    {
+    }
+
+    template<
+        bool isMutable_ = isMutable,
+        class = typename std::enable_if<
+            ! isMutable_>::type>
+    buffers_pair&
+    operator=(buffers_pair<true> const& other)
+    {
+        b_[0] = *other.begin();
+        b_[1] = *(other.begin() + 1);
+    }
+
+    buffers_pair(value_type b0, value_type b1)
+        : b_{b0, b1}
     {
-        BOOST_ASSERT(i >= 0 && i < 2);
-        return b_[i];
     }
 
     const_iterator
@@ -79,10 +97,15 @@ public:
             return &b_[2];
         return &b_[1];
     }
+
 private:
     value_type b_[2];
 };
 
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
+# pragma warning (pop)
+#endif
+
 } // detail
 } // beast
 } // boost
diff --git a/include/boost/beast/core/detail/tuple.hpp b/include/boost/beast/core/detail/tuple.hpp
index cb64b8b3..4c1098ba 100644
--- a/include/boost/beast/core/detail/tuple.hpp
+++ b/include/boost/beast/core/detail/tuple.hpp
@@ -25,6 +25,27 @@ template<std::size_t I, class T>
 struct tuple_element_impl
 {
     T t;
+
+    tuple_element_impl(T const& t_)
+        : t(t_)
+    {
+    }
+
+    tuple_element_impl(T&& t_)
+        : t(std::move(t_))
+    {
+    }
+};
+
+template<std::size_t I, class T>
+struct tuple_element_impl<I, T&>
+{
+    T& t;
+
+    tuple_element_impl(T& t_)
+        : t(t_)
+    {
+    }
 };
 
 template<class... Ts>
@@ -32,12 +53,13 @@ struct tuple_impl;
 
 template<class... Ts, std::size_t... Is>
 struct tuple_impl<
-        boost::mp11::index_sequence<Is...>, Ts...>
+    boost::mp11::index_sequence<Is...>, Ts...>
   : tuple_element_impl<Is, Ts>...
 {
     template<class... Us>
     explicit tuple_impl(Us&&... us)
-      : tuple_element_impl<Is, Ts>{std::forward<Us>(us)}...
+        : tuple_element_impl<Is, Ts>(
+            std::forward<Us>(us))...
     {
     }
 };
@@ -76,6 +98,13 @@ get(tuple_element_impl<I, T>&& te)
     return std::move(te.t);
 }
 
+template<std::size_t I, class T>
+T&
+get(tuple_element_impl<I, T&>&& te)
+{
+    return te.t;
+}
+
 template <std::size_t I, class T>
 using tuple_element = typename boost::copy_cv<
     mp11::mp_at_c<typename remove_cv<T>::type, I>, T>::type;
diff --git a/include/boost/beast/core/impl/multi_buffer.hpp b/include/boost/beast/core/impl/multi_buffer.hpp
index f11b8303..8bc73e3c 100644
--- a/include/boost/beast/core/impl/multi_buffer.hpp
+++ b/include/boost/beast/core/impl/multi_buffer.hpp
@@ -11,6 +11,7 @@
 #define BOOST_BEAST_IMPL_MULTI_BUFFER_HPP
 
 #include <boost/beast/core/detail/type_traits.hpp>
+#include <boost/config/workaround.hpp>
 #include <boost/core/exchange.hpp>
 #include <boost/assert.hpp>
 #include <boost/throw_exception.hpp>
@@ -125,6 +126,12 @@ public:
 
 //------------------------------------------------------------------------------
 
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
+# pragma warning (push)
+# pragma warning (disable: 4521) // multiple copy constructors specified
+# pragma warning (disable: 4522) // multiple assignment operators specified
+#endif
+
 template<class Allocator>
 template<bool IsMutable>
 class basic_multi_buffer<Allocator>::readable_bytes
@@ -149,8 +156,21 @@ public:
     class const_iterator;
 
     readable_bytes() = delete;
+#if ! defined(_MSC_VER) || (_MSC_VER >= 1910)
     readable_bytes(readable_bytes const&) = default;
     readable_bytes& operator=(readable_bytes const&) = default;
+#else
+    readable_bytes(readable_bytes const& other)
+        : b_(other.b_)
+    {
+    }
+
+    readable_bytes& operator=(readable_bytes const& other)
+    {
+        b_ = other.b_;
+        return *this;
+    }
+#endif
 
     template<
         bool IsMutable_ = IsMutable,
@@ -182,6 +202,10 @@ public:
     }
 };
 
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1910)
+# pragma warning (pop)
+#endif
+
 //------------------------------------------------------------------------------
 
 template<class Allocator>
diff --git a/include/boost/beast/core/impl/static_buffer.hpp b/include/boost/beast/core/impl/static_buffer.hpp
index 68a3b129..e272e37c 100644
--- a/include/boost/beast/core/impl/static_buffer.hpp
+++ b/include/boost/beast/core/impl/static_buffer.hpp
@@ -34,19 +34,17 @@ static_buffer_base::
 data() const noexcept ->
     const_buffers_type
 {
-    using net::const_buffer;
-    const_buffers_type result;
     if(in_off_ + in_size_ <= capacity_)
-    {
-        result[0] = const_buffer{begin_ + in_off_, in_size_};
-        result[1] = const_buffer{begin_, 0};
-    }
-    else
-    {
-        result[0] = const_buffer{begin_ + in_off_, capacity_ - in_off_};
-        result[1] = const_buffer{begin_, in_size_ - (capacity_ - in_off_)};
-    }
-    return result;
+        return {
+            net::const_buffer{
+                begin_ + in_off_, in_size_},
+            net::const_buffer{
+                begin_, 0}};
+    return {
+        net::const_buffer{
+            begin_ + in_off_, capacity_ - in_off_},
+        net::const_buffer{
+            begin_, in_size_ - (capacity_ - in_off_)}};
 }
 
 auto
@@ -54,19 +52,17 @@ static_buffer_base::
 data() noexcept ->
     mutable_data_type
 {
-    using net::mutable_buffer;
-    mutable_data_type result;
     if(in_off_ + in_size_ <= capacity_)
-    {
-        result[0] = mutable_buffer{begin_ + in_off_, in_size_};
-        result[1] = mutable_buffer{begin_, 0};
-    }
-    else
-    {
-        result[0] = mutable_buffer{begin_ + in_off_, capacity_ - in_off_};
-        result[1] = mutable_buffer{begin_, in_size_ - (capacity_ - in_off_)};
-    }
-    return result;
+        return {
+            net::mutable_buffer{
+                begin_ + in_off_, in_size_},
+            net::mutable_buffer{
+                begin_, 0}};
+    return {
+        net::mutable_buffer{
+            begin_ + in_off_, capacity_ - in_off_},
+        net::mutable_buffer{
+            begin_, in_size_ - (capacity_ - in_off_)}};
 }
 
 auto
@@ -79,19 +75,19 @@ prepare(std::size_t n) ->
         BOOST_THROW_EXCEPTION(std::length_error{
             "buffer overflow"});
     out_size_ = n;
-    auto const out_off = (in_off_ + in_size_) % capacity_;
-    mutable_buffers_type result;
+    auto const out_off =
+        (in_off_ + in_size_) % capacity_;
     if(out_off + out_size_ <= capacity_ )
-    {
-        result[0] = mutable_buffer{begin_ + out_off, out_size_};
-        result[1] = mutable_buffer{begin_, 0};
-    }
-    else
-    {
-        result[0] = mutable_buffer{begin_ + out_off, capacity_ - out_off};
-        result[1] = mutable_buffer{begin_, out_size_ - (capacity_ - out_off)};
-    }
-    return result;
+        return {
+            net::mutable_buffer{
+                begin_ + out_off, out_size_},
+            net::mutable_buffer{
+                begin_, 0}};
+    return {
+        net::mutable_buffer{
+            begin_ + out_off, capacity_ - out_off},
+        net::mutable_buffer{
+            begin_, out_size_ - (capacity_ - out_off)}};
 }
 
 void
diff --git a/test/beast/core/multi_buffer.cpp b/test/beast/core/multi_buffer.cpp
index 87846eca..d259a39f 100644
--- a/test/beast/core/multi_buffer.cpp
+++ b/test/beast/core/multi_buffer.cpp
@@ -46,7 +46,8 @@ public:
     BOOST_STATIC_ASSERT(std::is_convertible<
         multi_buffer::mutable_data_type,
         multi_buffer::const_buffers_type>::value);
-#if ! defined( BOOST_LIBSTDCXX_VERSION ) || BOOST_LIBSTDCXX_VERSION >= 50000
+#if ! BOOST_WORKAROUND(BOOST_LIBSTDCXX_VERSION, < 50000) && \
+    ! BOOST_WORKAROUND(BOOST_MSVC, < 1910)
     BOOST_STATIC_ASSERT(std::is_trivially_copyable<
         multi_buffer::const_buffers_type>::value);
     BOOST_STATIC_ASSERT(std::is_trivially_copyable<