Re: [SyncEvolution] [REVIEW REQUEST 2/7] GDBus GIO: add variant append support
On Fr, 2012-01-27 at 14:55 +0100, Mikel Astiz wrote:
+template <class V1, class V2 = append_visitor_dummy_type>
struct append_visitor : public boost::static_visitor<>
+{
+ GVariantBuilder &builder;
+ append_visitor(GVariantBuilder &b) : builder(b) {}
+ void operator()(const V1 &v) const
+ {
+ dbus_traits<V1>::append(builder, v);
+ }
+ void operator()(const V2 &v) const
+ {
+ dbus_traits<V2>::append(builder, v);
+ }
+};
I think this could be simplified to
struct append_visitor : public boost::static_visitor<>
{
GVariantBuilder &builder;
append_visitor(GVariantBuilder &b) : builder(b) {}
template <class V> void operator()(const V &v) const
{
dbus_traits<V>::append(builder, v);
}
};
I'm wondering how it works, though. In libdbus, the iterator for the
variant must be opened with the type of the *value* in the variant. Here
the GVariantBuilder is opened with G_VARIANT_TYPE("v"), the type of the
*variant* itself:
static std::string getType() { return "v"; }
...
static void append(GVariantBuilder &builder, const boost::variant<V>
&value)
{
g_variant_builder_open(&builder, G_VARIANT_TYPE(getType().c_str()));
boost::apply_visitor(append_visitor<V>(builder), value);
g_variant_builder_close(&builder);
}
I checked with dbus-monitor, the resulting D-Bus message has "variant
string" as type of value, as intended.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
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