+struct : ldid::Progress {
+ virtual void operator()(const std::string &value) const {
+ }
+
+ virtual void operator()(double value) const {
+ }
+} dummy_;
+
+struct Progression : ldid::Progress {
+ const ldid::Progress &progress_;
+ std::string name_;
+
+ Progression(const ldid::Progress &progress, const std::string &name) :
+ progress_(progress),
+ name_(name)
+ {
+ }
+
+ virtual void operator()(const std::string &value) const {
+ return progress_(name_ + " (" + value + ")");
+ }
+
+ virtual void operator()(double value) const {
+ return progress_(value);
+ }
+};