From 4f1ff4952df682c6dfe243fd4e879c9aaec06af2 Mon Sep 17 00:00:00 2001
From: Gudmundur Adalsteinsson <ofpgummi@yahoo.com>
Date: Fri, 30 Aug 2019 23:14:16 +0000
Subject: [PATCH] Fix for lacking SFINAE support on older GCC

---
 tests/utilities.cpp | 18 +++++++++---------
 zmq.hpp             |  8 ++++++--
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/tests/utilities.cpp b/tests/utilities.cpp
index c7b8c99..9f1e2f2 100644
--- a/tests/utilities.cpp
+++ b/tests/utilities.cpp
@@ -1,7 +1,7 @@
 #include <catch.hpp>
 #include <zmq.hpp>
 
-#ifdef ZMQ_CPP11
+#if defined(ZMQ_CPP11) && !defined(ZMQ_CPP11_PARTIAL)
 
 namespace test_ns
 {
@@ -16,11 +16,11 @@ struct T_mr
 struct T_fr
 {
 };
-void *begin(const T_fr &) noexcept
+inline void *begin(const T_fr &) noexcept
 {
     return nullptr;
 }
-void *end(const T_fr &) noexcept
+inline void *end(const T_fr &) noexcept
 {
     return nullptr;
 }
@@ -29,11 +29,11 @@ struct T_mfr
     void *begin() const noexcept { return nullptr; }
     void *end() const noexcept { return nullptr; }
 };
-void *begin(const T_mfr &) noexcept
+inline void *begin(const T_mfr &) noexcept
 {
     return nullptr;
 }
-void *end(const T_mfr &) noexcept
+inline void *end(const T_mfr &) noexcept
 {
     return nullptr;
 }
@@ -50,11 +50,11 @@ struct T_assoc_ns_mr : std::exception
 struct T_assoc_ns_fr : std::exception
 {
 };
-void *begin(const T_assoc_ns_fr &) noexcept
+inline void *begin(const T_assoc_ns_fr &) noexcept
 {
     return nullptr;
 }
-void *end(const T_assoc_ns_fr &) noexcept
+inline void *end(const T_assoc_ns_fr &) noexcept
 {
     return nullptr;
 }
@@ -63,11 +63,11 @@ struct T_assoc_ns_mfr : std::exception
     void *begin() const noexcept { return nullptr; }
     void *end() const noexcept { return nullptr; }
 };
-void *begin(const T_assoc_ns_mfr &) noexcept
+inline void *begin(const T_assoc_ns_mfr &) noexcept
 {
     return nullptr;
 }
-void *end(const T_assoc_ns_mfr &) noexcept
+inline void *end(const T_assoc_ns_mfr &) noexcept
 {
     return nullptr;
 }
diff --git a/zmq.hpp b/zmq.hpp
index 3b76a78..c86be81 100644
--- a/zmq.hpp
+++ b/zmq.hpp
@@ -122,8 +122,12 @@
 #define ZMQ_DELETED_FUNCTION
 #endif
 
+#if defined(ZMQ_CPP11) && defined(__GNUC__) && __GNUC__ < 5
+#define ZMQ_CPP11_PARTIAL
+#endif
+
 #ifdef ZMQ_CPP11
-#if defined(__GNUC__) && __GNUC__ < 5
+#ifdef ZMQ_CPP11_PARTIAL
 #define ZMQ_IS_TRIVIALLY_COPYABLE(T) __has_trivial_copy(T)
 #else
 #define ZMQ_IS_TRIVIALLY_COPYABLE(T) std::is_trivially_copyable<T>::value
@@ -335,7 +339,7 @@ class message_t
             throw error_t();
     }
 
-#ifdef ZMQ_CPP11
+#if defined(ZMQ_CPP11) && !defined(ZMQ_CPP11_PARTIAL)
     template<class Range,
              typename = typename std::enable_if<
                detail::is_range<Range>::value