[Positioner] Allow building with clang++

This patch is to have clang++ (>= 3.2) happily build OwlPS Positioner.
For some reason it doesn't work on NetBSD, but it is fine on GNU/Linux
and (a couple of warnings apart) on DragonFly BSD.

CMakeLists.txt

@@ -177,26 +177,38 @@ endif()
 
 ## Positioner ##
 
-# OwlPS Positioner can be built only with GCC, and with a minimal
-# version. CMAKE_CXX_COMPILER_VERSION is not guaranteed to be set,
-# so we will test GCC's version number only if possible.
+# OwlPS Positioner can be built only with a minimal version of GCC, or
+# Clang++. CMAKE_CXX_COMPILER_VERSION is not guaranteed to be set, so we
+# will test the version number only if possible.
 set(POSITIONER_MIN_GCC_VERSION 4.7)
-if (CMAKE_COMPILER_IS_GNUCXX)
+set(POSITIONER_MIN_CLANG_VERSION 3.2)
+
+if (CMAKE_CXX_COMPILER_ID STREQUAL GNU) # Are we using GCC?
   # Test the compiler version if we can
-  if (${CMAKE_CXX_COMPILER_VERSION})
-    if (${CMAKE_CXX_COMPILER_VERSION} VERSION_EQUAL ${POSITIONER_MIN_GCC_VERSION} OR
-        ${CMAKE_CXX_COMPILER_VERSION} VERSION_GREATER ${POSITIONER_MIN_GCC_VERSION})
-      add_subdirectory(owlps-positioner)
-    else() # GCC's version is too low
-      message(WARNING
-        "OwlPS Positioner requires GCC >= ${POSITIONER_MIN_GCC_VERSION}")
-    endif()
-  else() # we couldn't get GCC's version, let's try to build anyway
+  if (${CMAKE_CXX_COMPILER_VERSION} AND
+      ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS ${POSITIONER_MIN_GCC_VERSION})
+    # GCC's version is too low
+    message(WARNING
+      "OwlPS Positioner requires GCC >= ${POSITIONER_MIN_GCC_VERSION}")
+  else()
+    # GCC's version is OK or we couldn'd get it
     add_subdirectory(owlps-positioner)
   endif()
+
+elseif (CMAKE_CXX_COMPILER_ID STREQUAL Clang) # Are we using Clang?
+  if (${CMAKE_CXX_COMPILER_VERSION} AND
+      ${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS ${POSITIONER_MIN_CLANG_VERSION})
+    # Clang's version is too low
+    message(WARNING
+      "OwlPS Positioner requires GCC >= ${POSITIONER_MIN_GCC_VERSION}")
+  else()
+    # Clang's version is OK or we couldn'd get it
+    add_subdirectory(owlps-positioner)
+  endif()
+
 else() # we're not using GCC
   message(WARNING
-    "OwlPS Positioner requires GCC (>= ${POSITIONER_MIN_GCC_VERSION})")
+    "OwlPS Positioner requires GCC (>= ${POSITIONER_MIN_GCC_VERSION}) or Clang (>= ${POSITIONER_MIN_CLANG_VERSION})")
 endif()
 
 ## UDP-to-HTTP ##

INSTALL.t2t

@@ -17,7 +17,8 @@ systems” below) with the following development libraries installed:
 
 You also need support for POSIX threads, which should be provided by
 default by your system in most cases, and the GCC C++ compiler (g++)
-version 4.7 or above.
+version 4.7 or above; the Clang C++ compiler (clang++) version 3.2 or
+above should also work in most cases.
 
 If you miss one or more of the requirements, the concerned modules will
 not be built, but the others can still be.

owlps-positioner/src/calibrationrequest.cc

@@ -20,7 +20,7 @@
 
 
 CalibrationRequest::
-CalibrationRequest(uint_fast8_t _type = OWL_REQUEST_AUTOCALIBRATION):
+CalibrationRequest(uint_fast8_t _type):
   reference_point(NULL), direction(Direction())
 {
   type = _type ;

owlps-positioner/src/calibrationrequest.hh

@@ -30,7 +30,7 @@ protected:
   Direction direction ;
 
 public:
-  CalibrationRequest(uint_fast8_t _type) ;
+  CalibrationRequest(uint_fast8_t _type = OWL_REQUEST_AUTOCALIBRATION) ;
 
   CalibrationRequest(const CalibrationRequest &source):
     Request(source), reference_point(source.reference_point),

owlps-positioner/src/request.hh

@@ -54,20 +54,29 @@ protected:
   void clear_real_position(void) ;
   //@}
 
+  /// Measurements' list type
+  /**
+   * This really is just an alias to work-around clang++ that doesn't
+   * handle the following syntax:
+   *
+   *     Request(..., const std::unordered_map<std::string, Measurement>
+   *       &_measurements = std::unordered_map<std::string,
+   *                                           Measurement>()) ;
+   */
+  typedef std::unordered_map<std::string, Measurement> measurements_list ;
+
 public:
   Request(const Mobile *_mobile = NULL,
           const Timestamp &_time_sent = Timestamp(),
           const std::unordered_map<std::string, Measurement>
-          &_measurements =
-            std::unordered_map<std::string, Measurement>()) ;
+          &_measurements = measurements_list()) ;
 
   Request(const std::unordered_map<std::string, Measurement>
           &_measurements) ;
 
   Request(const Timestamp &_time_sent,
           const std::unordered_map<std::string, Measurement>
-          &_measurements =
-            std::unordered_map<std::string, Measurement>()) ;
+          &_measurements = measurements_list()) ;
 
   Request(const Request &source) ;
 

owlps-positioner/src/wifidevice.hh

@@ -37,10 +37,10 @@ protected:
   float trx_power ; ///< Transmit power in dBm
 
 public:
-  WifiDevice(const std::string &_ip_addr,
-             const std::string &_mac_addr,
-             const float _antenna_gain,
-             const float _trx_power) ;
+  WifiDevice(const std::string &_ip_addr = "",
+             const std::string &_mac_addr = "",
+             const float _antenna_gain = WIFIDEVICE_DEFAULT_ANTENNA_GAIN,
+             const float _trx_power = WIFIDEVICE_DEFAULT_TRX_POWER) ;
 
   WifiDevice(const WifiDevice &source):
     ip_addr(source.ip_addr), mac_addr(source.mac_addr),
@@ -81,10 +81,10 @@ public:
 
 
 inline WifiDevice::
-WifiDevice(const std::string &_ip_addr = "",
-           const std::string &_mac_addr = "",
-           const float _antenna_gain = WIFIDEVICE_DEFAULT_ANTENNA_GAIN,
-           const float _trx_power = WIFIDEVICE_DEFAULT_TRX_POWER):
+WifiDevice(const std::string &_ip_addr,
+           const std::string &_mac_addr,
+           const float _antenna_gain,
+           const float _trx_power):
   ip_addr(_ip_addr), mac_addr(_mac_addr),
   antenna_gain(_antenna_gain), trx_power(_trx_power)
 {