Make signal_cast template

Author: jmirabel

include/dynamic-graph/signal-caster.h

@@ -18,6 +18,7 @@
 #include "dynamic-graph/exception-signal.h"
 #include <dynamic-graph/dynamic-graph-api.h>
 #include <dynamic-graph/linear-algebra.h>
+#include <dynamic-graph/eigen-io.h>
 
 namespace dynamicgraph {
 /// This singleton class allows serialization of a number of objects into
@@ -109,9 +110,56 @@ template <> struct signal_disp<std::string> {
 inline static void run (const std::string &value, std::ostream &os) { os << value; }
 };
 
-template <typename T> T signal_cast(std::istringstream &iss) {
-  return boost::any_cast<T>(SignalCaster::getInstance()->cast(typeid(T), iss));
+/// Template class used to deserialize a signal value (reverse of signal_disp).
+template <typename T> struct signal_cast {
+inline static T run (std::istringstream &iss) {
+  T inst;
+  iss >> inst;
+  if (iss.fail()) {
+    throw ExceptionSignal(ExceptionSignal::GENERIC,
+        "failed to serialize " + iss.str());
+  }
+  return inst;
 }
+};
+
+/// Template specialization of signal_cast for std::string.
+template <> struct signal_cast<std::string> {
+inline static std::string run (std::istringstream &iss) { return iss.str(); }
+};
+
+/// Template specialization of signal_cast for double
+/// to workaround the limitations of the stream based approach.
+///
+/// When dealing with double: displaying a double on a stream
+/// is *NOT* the opposite of reading a double from a stream.
+///
+/// In practice, it means that there is no way to read
+/// a NaN, +inf, -inf from a stream!
+///
+/// To workaround this problem, parse special values manually
+/// (the strings used are the one produces by displaying special
+/// values on a stream).
+template <> struct signal_cast<double> {
+inline static double run (std::istringstream &iss) {
+  std::string tmp (iss.str());
+
+  if (tmp == "nan")
+    return std::numeric_limits<double>::quiet_NaN();
+  else if (tmp == "inf" || tmp == "+inf")
+    return std::numeric_limits<double>::infinity();
+  else if (tmp == "-inf")
+    return -1. * std::numeric_limits<double>::infinity();
+
+  try {
+    return boost::lexical_cast<double>(tmp);
+  } catch (boost::bad_lexical_cast &) {
+    boost::format fmt("failed to serialize %s (to double)");
+    fmt % tmp;
+    throw ExceptionSignal(ExceptionSignal::GENERIC, fmt.str());
+  }
+}
+};
 
 /// Template class used to display a signal value.
 template <typename T> struct signal_trace {

include/dynamic-graph/signal.t.cpp

@@ -30,7 +30,7 @@ Signal<T, Time>::Signal(std::string name)
 
 template <class T, class Time>
 void Signal<T, Time>::set(std::istringstream &stringValue) {
-  (*this) = signal_cast<T>(stringValue);
+  (*this) = signal_cast<T>::run(stringValue);
 }
 
 template <class T, class Time>