Merge pull request #2922 from mapnik/value-ostream-fix

fix #2921

include/mapnik/value.hpp

@@ -958,7 +958,6 @@ inline std::size_t hash_value(value const& val)
 } // namespace value_adl_barrier
 
 using value_adl_barrier::value;
-using value_adl_barrier::operator<<;
 
 namespace detail {
 

test/unit/core/conversions_test.cpp

@@ -2,11 +2,14 @@
 
 #include <mapnik/value_types.hpp>
 #include <mapnik/value.hpp>
+#include <mapnik/unicode.hpp>
 #include <mapnik/util/conversions.hpp>
+
 #include <iostream>
 #include <vector>
 #include <algorithm>
 #include <unordered_map>
+#include <sstream>
 
 #if defined(_MSC_VER) && _MSC_VER < 1900
 #include <cstdio>
@@ -289,6 +292,14 @@ SECTION("to string") {
         vc[val2] = 1;
         REQUIRE( vc[1] == static_cast<int>(1) );
 
+        // mapnik::value << to ostream
+        std::stringstream s;
+        mapnik::transcoder tr("utf-8");
+        mapnik::value_unicode_string ustr = tr.transcode("hello world!");
+        mapnik::value streamable(ustr);
+        s << streamable;
+        CHECK( s.str() == std::string("hello world!") );
+
     }
     catch (std::exception const & ex)
     {

test/unit/imaging/image.cpp

@@ -1,6 +1,7 @@
 #include "catch.hpp"
 
 // mapnik
+#include <mapnik/value.hpp>
 #include <mapnik/image_any.hpp>
 #include <mapnik/color.hpp>
 #include <mapnik/image_view_any.hpp>