From 99d98dd217d1fb6767a964aa3f2ea194ebf1f109 Mon Sep 17 00:00:00 2001
From: Gudmundur Adalsteinsson <ofpgummi@yahoo.com>
Date: Thu, 9 May 2019 22:33:49 +0000
Subject: [PATCH] Improved enum flags operators and tests

---
 tests/socket.cpp | 22 ++++++++++++++++-
 zmq.hpp          | 64 +++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 82 insertions(+), 4 deletions(-)

diff --git a/tests/socket.cpp b/tests/socket.cpp
index 80962b1..92e7893 100644
--- a/tests/socket.cpp
+++ b/tests/socket.cpp
@@ -46,7 +46,27 @@ TEST_CASE("socket swap", "[socket]")
     using std::swap;
     swap(socket1, socket2);
 }
-TEST_CASE("rass", "[socket]")
+
+TEST_CASE("socket flags", "[socket]")
+{
+    CHECK((zmq::recv_flags::dontwait | zmq::recv_flags::none)
+          == static_cast<zmq::recv_flags>(ZMQ_DONTWAIT | 0));
+    CHECK((zmq::recv_flags::dontwait & zmq::recv_flags::none)
+          == static_cast<zmq::recv_flags>(ZMQ_DONTWAIT & 0));
+    CHECK((zmq::recv_flags::dontwait ^ zmq::recv_flags::none)
+          == static_cast<zmq::recv_flags>(ZMQ_DONTWAIT ^ 0));
+    CHECK(~zmq::recv_flags::dontwait == static_cast<zmq::recv_flags>(~ZMQ_DONTWAIT));
+
+    CHECK((zmq::send_flags::dontwait | zmq::send_flags::sndmore)
+          == static_cast<zmq::send_flags>(ZMQ_DONTWAIT | ZMQ_SNDMORE));
+    CHECK((zmq::send_flags::dontwait & zmq::send_flags::sndmore)
+          == static_cast<zmq::send_flags>(ZMQ_DONTWAIT & ZMQ_SNDMORE));
+    CHECK((zmq::send_flags::dontwait ^ zmq::send_flags::sndmore)
+          == static_cast<zmq::send_flags>(ZMQ_DONTWAIT ^ ZMQ_SNDMORE));
+    CHECK(~zmq::send_flags::dontwait == static_cast<zmq::send_flags>(~ZMQ_DONTWAIT));
+}
+
+TEST_CASE("socket readme example", "[socket]")
 {
     zmq::context_t ctx;
     zmq::socket_t sock(ctx, zmq::socket_type::push);
diff --git a/zmq.hpp b/zmq.hpp
index c3d262e..f8acb29 100644
--- a/zmq.hpp
+++ b/zmq.hpp
@@ -645,6 +645,39 @@ struct recv_buffer_result
     }
 };
 
+namespace detail
+{
+template<class T>
+constexpr T enum_bit_or(T a, T b) noexcept
+{
+    static_assert(std::is_enum<T>::value, "must be enum");
+    using U = typename std::underlying_type<T>::type;
+    return static_cast<T>(static_cast<U>(a) | static_cast<U>(b));
+}
+template<class T>
+constexpr T enum_bit_and(T a, T b) noexcept
+{
+    static_assert(std::is_enum<T>::value, "must be enum");
+    using U = typename std::underlying_type<T>::type;
+    return static_cast<T>(static_cast<U>(a) & static_cast<U>(b));
+}
+template<class T>
+constexpr T enum_bit_xor(T a, T b) noexcept
+{
+    static_assert(std::is_enum<T>::value, "must be enum");
+    using U = typename std::underlying_type<T>::type;
+    return static_cast<T>(static_cast<U>(a) ^ static_cast<U>(b));
+}
+template<class T>
+constexpr T enum_bit_not(T a) noexcept
+{
+    static_assert(std::is_enum<T>::value, "must be enum");
+    using U = typename std::underlying_type<T>::type;
+    return static_cast<T>(~static_cast<U>(a));
+}
+} // namespace detail
+
+// partially satisfies named requirement BitmaskType
 enum class send_flags : int
 {
     none = 0,
@@ -654,10 +687,22 @@ enum class send_flags : int
 
 constexpr send_flags operator|(send_flags a, send_flags b) noexcept
 {
-    return static_cast<send_flags>(static_cast<std::underlying_type<send_flags>::type>(a)
-        | static_cast<<std::underlying_type<send_flags>::type>(b));
+    return detail::enum_bit_or(a, b);
+}
+constexpr send_flags operator&(send_flags a, send_flags b) noexcept
+{
+    return detail::enum_bit_and(a, b);
+}
+constexpr send_flags operator^(send_flags a, send_flags b) noexcept
+{
+    return detail::enum_bit_xor(a, b);
+}
+constexpr send_flags operator~(send_flags a) noexcept
+{
+    return detail::enum_bit_not(a);
 }
 
+// partially satisfies named requirement BitmaskType
 enum class recv_flags : int
 {
     none = 0,
@@ -666,8 +711,21 @@ enum class recv_flags : int
 
 constexpr recv_flags operator|(recv_flags a, recv_flags b) noexcept
 {
-    return static_cast<recv_flags>(static_cast<int>(a) | static_cast<int>(b));
+    return detail::enum_bit_or(a, b);
 }
+constexpr recv_flags operator&(recv_flags a, recv_flags b) noexcept
+{
+    return detail::enum_bit_and(a, b);
+}
+constexpr recv_flags operator^(recv_flags a, recv_flags b) noexcept
+{
+    return detail::enum_bit_xor(a, b);
+}
+constexpr recv_flags operator~(recv_flags a) noexcept
+{
+    return detail::enum_bit_not(a);
+}
+
 
 // mutable_buffer, const_buffer and buffer are based on
 // the Networking TS specification, draft: