Serialize new item members

I forgot to add serialization for `tools_to_continue` and
`cached_tool_selections` which were added to `item` in a previous
commit.

This commit adds io support for `comp_selection` and properly
serializes the new item members.

src/craft_command.cpp

@@ -9,7 +9,9 @@
 #include "debug.h"
 #include "game_constants.h"
 #include "inventory.h"
+#include "io.h"
 #include "item.h"
+#include "json.h"
 #include "output.h"
 #include "player.h"
 #include "recipe.h"
@@ -35,6 +37,70 @@ std::string comp_selection<CompType>::nname() const
     return item::nname( comp.type, comp.count );
 }
 
+namespace io
+{
+
+static const std::map<std::string, usage> usage_map = {{
+        { "map", usage::use_from_map },
+        { "player", usage::use_from_player },
+        { "both", usage::use_from_both },
+        { "none", usage::use_from_none },
+        { "cancel", usage::cancel }
+    }
+};
+
+template<>
+usage string_to_enum<usage>( const std::string &data )
+{
+    return string_to_enum_look_up( usage_map, data );
+}
+
+template<>
+const std::string enum_to_string<usage>( usage data )
+{
+    const auto iter = std::find_if( usage_map.begin(), usage_map.end(),
+    [data]( const std::pair<std::string, usage> &kv ) {
+        return kv.second == data;
+    } );
+
+    if( iter == usage_map.end() ) {
+        throw InvalidEnumString{};
+    }
+
+    return iter->first;
+}
+
+} // namespace io
+
+template<typename CompType>
+void comp_selection<CompType>::serialize( JsonOut &jsout ) const
+{
+    jsout.start_object();
+
+    jsout.member( "use_from", io::enum_to_string( use_from ) );
+    jsout.member( "type", comp.type );
+    jsout.member( "count", comp.count );
+
+    jsout.end_object();
+}
+
+template<typename CompType>
+void comp_selection<CompType>::deserialize( JsonIn &jsin )
+{
+    JsonObject data = jsin.get_object();
+
+    std::string use_from_str;
+    data.read( "use_from", use_from_str );
+    use_from = io::string_to_enum<usage>( use_from_str );
+    data.read( "type", comp.type );
+    data.read( "count", comp.count );
+}
+
+template void comp_selection<tool_comp>::serialize( JsonOut &jsout ) const;
+template void comp_selection<item_comp>::serialize( JsonOut &jsout ) const;
+template void comp_selection<tool_comp>::deserialize( JsonIn &jsin );
+template void comp_selection<item_comp>::deserialize( JsonIn &jsin );
+
 void craft_command::execute( const tripoint &new_loc )
 {
     if( empty() ) {

src/craft_command.h

@@ -35,6 +35,9 @@ struct comp_selection {
 
     /** provides a translated name for 'comp', suffixed with it's location e.g '(nearby)'. */
     std::string nname() const;
+
+    void serialize( JsonOut &jsout ) const;
+    void deserialize( JsonIn &jsin );
 };
 
 /**

src/savegame_json.cpp

@@ -29,6 +29,7 @@
 #include "basecamp.h"
 #include "bionics.h"
 #include "calendar.h"
+#include "craft_command.h"
 #include "debug.h"
 #include "effect.h"
 #include "game.h"
@@ -2019,6 +2020,8 @@ void item::io( Archive &archive )
     archive.io( "light_dir", light.direction, nolight.direction );
     archive.io( "comps_used", comps_used, io::empty_default_tag() );
     archive.io( "next_failure_point", next_failure_point, -1 );
+    archive.io( "tools_to_continue", tools_to_continue, false );
+    archive.io( "cached_tool_selections", cached_tool_selections, io::empty_default_tag() );
 
     item_controller->migrate_item( orig, *this );