Merge pull request #116 from boostorg/feature/span_boost_begin_test

Add test around the MSVC defect

test/Jamfile.v2

@@ -331,6 +331,7 @@ run span_constructible_test.cpp ;
 run span_deduction_guide_test.cpp ;
 run as_bytes_test.cpp ;
 run as_writable_bytes_test.cpp ;
+compile span_boost_begin_test.cpp ;
 
 run splitmix64_test.cpp
   : : : $(pedantic-errors) ;

test/span_boost_begin_test.cpp

@@ -0,0 +1,37 @@
+/*
+Copyright 2022 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/config.hpp>
+#if !defined(BOOST_NO_CXX11_CONSTEXPR) && !defined(BOOST_NO_CXX11_DECLTYPE)
+#include <boost/core/span.hpp>
+#include <vector>
+
+namespace boost {
+namespace begin_ {
+
+template<class T>
+void begin(T&) { }
+
+} // begin_
+
+using namespace begin_;
+
+} // boost
+
+template class boost::span<float>;
+
+void function()
+{
+    std::vector<int> y;
+    boost::begin(y);
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif