Allow -1.0 as unlimited for default_radius value (#6599)

src/tools/routed.cpp

@@ -12,6 +12,7 @@
 #include <boost/algorithm/string/case_conv.hpp>
 #include <boost/any.hpp>
 #include <boost/filesystem.hpp>
+#include <boost/optional/optional_io.hpp>
 #include <boost/program_options.hpp>
 
 #include <cstdlib>
@@ -70,6 +71,33 @@ std::istream &operator>>(std::istream &in, EngineConfig::Algorithm &algorithm)
 }
 } // namespace osrm::engine
 
+// overload validate for the double type to allow "unlimited" as an input
+namespace boost
+{
+void validate(boost::any &v, const std::vector<std::string> &values, double *, double)
+{
+    boost::program_options::validators::check_first_occurrence(v);
+    const std::string &s = boost::program_options::validators::get_single_string(values);
+
+    if (s == "unlimited")
+    {
+        v = -1.0;
+    }
+    else
+    {
+        try
+        {
+            v = std::stod(s);
+        }
+        catch (const std::invalid_argument &)
+        {
+            throw boost::program_options::validation_error(
+                boost::program_options::validation_error::invalid_option_value);
+        }
+    }
+}
+} // namespace boost
+
 // generate boost::program_options object for the routing part
 inline unsigned generateServerProgramOptions(const int argc,
                                              const char *argv[],
@@ -149,7 +177,7 @@ inline unsigned generateServerProgramOptions(const int argc,
          value<double>(&config.max_radius_map_matching)->default_value(-1.0),
          "Max. radius size supported in map matching query. Default: unlimited.") //
         ("default-radius",
-         value<boost::optional<double>>(&config.default_radius),
+         value<boost::optional<double>>(&config.default_radius)->default_value(-1.0),
          "Default radius size for queries. Default: unlimited.");
 
     // hidden options, will be allowed on command line, but will not be shown to the user