Add a deleted constructor from nullptr_t to string_view; closes #113

include/boost/core/detail/string_view.hpp

@@ -403,6 +403,22 @@ public:
     {
     }
 
+#if !defined(BOOST_NO_CXX11_NULLPTR)
+# if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS)
+
+    basic_string_view( std::nullptr_t ) = delete;
+
+# else
+
+private:
+
+    basic_string_view( std::nullptr_t );
+
+public:
+
+# endif
+#endif
+
     // BOOST_CONSTEXPR basic_string_view& operator=( basic_string_view const& ) BOOST_NOEXCEPT & = default;
 
     // conversions

test/Jamfile.v2

@@ -327,6 +327,8 @@ run sv_conversion_test2.cpp : ;
 run sv_common_reference_test.cpp ;
 compile sv_common_reference_test2.cpp ;
 compile sv_windows_h_test.cpp ;
+compile-fail sv_nullptr_fail.cpp
+  : $(warning-as-errors-off) ;
 
 run span_test.cpp ;
 run span_types_test.cpp ;

test/sv_nullptr_fail.cpp

@@ -0,0 +1,10 @@
+// Copyright 2022 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/detail/string_view.hpp>
+
+int main()
+{
+    return boost::core::string_view( nullptr ).size() == 0;
+}