object node::search_namespace_by_prefix(value const &prefix_) {
local_root_scope scope;
xmlChar const *prefix = 0;
if (!prefix_.is_string() && !prefix_.is_undefined() && !prefix_.is_null())
throw exception("Could not search for non-string namespace prefix");
if (prefix_.is_string())
prefix = (xmlChar const *) prefix_.get_string().c_str();
xmlNsPtr ns = xmlSearchNs(ptr->doc, ptr, prefix);
return namespace_::create(ns);
}
virtual TPointer create(const extraction_context& context, const value& from) const override
{
using std::begin;
using std::end;
if (_check_null_input && from.is_null())
return TPointer();
auto iter = std::find_if(begin(_subtype_ctors), end(_subtype_ctors),
[&] (const std::pair<match_predicate, create_function>& pair)
{
return pair.first(context, from);
}
);
if (iter != end(_subtype_ctors))
return iter->second(context, from);
else
throw extraction_error(context,
std::string("No discriminators matched JSON value: ") + to_string(from)
);
}
boost::optional<T> perform(value const &v) {
if (v.is_undefined() || v.is_null())
return boost::optional<T>();
return base.perform(v);
}