Add operator<< for source_location

include/boost/assert/source_location.hpp

@@ -10,6 +10,7 @@
 #include <boost/current_function.hpp>
 #include <boost/config.hpp>
 #include <boost/cstdint.hpp>
+#include <iosfwd>
 
 namespace boost
 {
@@ -54,6 +55,29 @@ public:
     }
 };
 
+template<class E, class T> std::basic_ostream<E, T> & operator<<( std::basic_ostream<E, T> & os, source_location const & loc )
+{
+    os.width( 0 );
+
+    if( loc.line() == 0 )
+    {
+        os << "(unknown source location)";
+    }
+    else
+    {
+        os << loc.file_name() << ':' << loc.line();
+
+        if( loc.column() )
+        {
+            os << ':' << loc.column();
+        }
+
+        os << ": in function '" << loc.function_name() << '\'';
+    }
+
+    return os;
+}
+
 } // namespace boost
 
 #if defined( BOOST_DISABLE_CURRENT_LOCATION )

test/Jamfile.v2

@@ -37,3 +37,4 @@ run current_function_test2.cpp ;
 
 run source_location_test.cpp ;
 run source_location_test2.cpp ;
+run source_location_test3.cpp ;

test/source_location_test3.cpp

@@ -0,0 +1,30 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/assert/source_location.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <sstream>
+
+int main()
+{
+    {
+        boost::source_location loc;
+
+        std::ostringstream os;
+        os << loc;
+
+        BOOST_TEST_EQ( os.str(), std::string( "(unknown source location)" ) );
+    }
+
+    {
+        boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        std::ostringstream os;
+        os << loc;
+
+        BOOST_TEST_EQ( os.str(), std::string( __FILE__ ) + ":21: in function '" + BOOST_CURRENT_FUNCTION + "'" );
+    }
+
+    return boost::report_errors();
+}