Proper C++ version detection

libuavcan/include/uavcan/impl_constants.hpp

@@ -16,6 +16,21 @@
 namespace uavcan
 {
 
+/**
+ * UAVCAN can be compiled in C++11 mode.
+ * This macro allows to detect which version of the C++ standard is being used.
+ */
+#define UAVCAN_CPP11    2011
+#define UAVCAN_CPP03    2003
+
+#if __cplusplus > 201200
+# error Unsupported C++ standard
+#elif (__cplusplus > 201100) || defined(__GXX_EXPERIMENTAL_CXX0X__)
+# define UAVCAN_CPP_VERSION    UAVCAN_CPP11
+#else
+# define UAVCAN_CPP_VERSION    UAVCAN_CPP03
+#endif
+
 /**
  * UAVCAN can be explicitly told to ignore exceptions, or it can be detected automatically.
  */

libuavcan/include/uavcan/marshal/float_spec.hpp

@@ -8,12 +8,16 @@
 #include <limits>
 #include <uavcan/data_type.hpp>
 #include <uavcan/util/compile_time.hpp>
+#include <uavcan/impl_constants.hpp>
 #include <uavcan/marshal/type_util.hpp>
 #include <uavcan/marshal/integer_spec.hpp>
-#if __cplusplus > 201100
-#  include <cmath>
-#else
-#  include <math.h>
+#include <cmath>
+
+#ifndef UAVCAN_CPP_VERSION
+# error UAVCAN_CPP_VERSION
+#endif
+#if UAVCAN_CPP_VERSION < UAVCAN_CPP11
+# include <math.h>     // Needed for isfinite()
 #endif
 
 namespace uavcan

libuavcan/include/uavcan/util/lazy_constructor.hpp

@@ -8,6 +8,10 @@
 #include <uavcan/fatal_error.hpp>
 #include <uavcan/impl_constants.hpp>
 
+#ifndef UAVCAN_CPP_VERSION
+# error UAVCAN_CPP_VERSION
+#endif
+
 namespace uavcan
 {
 
@@ -31,7 +35,7 @@ class LazyConstructor
 
     template <typename U> struct ParamType { typedef const U& Type; };
     template <typename U> struct ParamType<U&> { typedef U& Type; };
-#if __cplusplus > 201100
+#if UAVCAN_CPP_VERSION >= UAVCAN_CPP11
     template <typename U> struct ParamType<U&&> { typedef U&& Type; };
 #endif