Move receiver_type from PVT/adapters to PVT/libs, make it buildable with pre C++17

src/algorithms/PVT/adapters/CMakeLists.txt

@@ -10,14 +10,12 @@ if(USE_CMAKE_TARGET_SOURCES)
     target_sources(pvt_adapters
         PRIVATE
             rtklib_pvt.cc
-            receiver_type.cc
         PUBLIC
             rtklib_pvt.h
-            receiver_type.h
     )
 else()
-    source_group(Headers FILES rtklib_pvt.h receiver_type.h)
+    source_group(Headers FILES rtklib_pvt.h)
-    add_library(pvt_adapters rtklib_pvt.cc rtklib_pvt.h receiver_type.h receiver_type.cc)
+    add_library(pvt_adapters rtklib_pvt.cc rtklib_pvt.h)
 endif()
 
 target_link_libraries(pvt_adapters

src/algorithms/PVT/adapters/rtklib_pvt.cc

@@ -21,6 +21,7 @@
 #include "galileo_almanac.h"           // for Galileo_Almanac
 #include "galileo_ephemeris.h"         // for Galileo_Ephemeris
 #include "gnss_sdr_flags.h"            // for FLAGS_RINEX_version
+#include "gnss_sdr_string_literals.h"  // for std::string_literals in C++11
 #include "gps_almanac.h"               // for Gps_Almanac
 #include "gps_ephemeris.h"             // for Gps_Ephemeris
 #include "pvt_conf.h"                  // for Pvt_Conf

src/algorithms/PVT/libs/CMakeLists.txt

@@ -24,6 +24,7 @@ set(PVT_LIB_SOURCES
     has_simple_printer.cc
     geohash.cc
     pvt_kf.cc
+    receiver_type.cc
 )
 
 set(PVT_LIB_HEADERS
@@ -47,6 +48,7 @@ set(PVT_LIB_HEADERS
     has_simple_printer.h
     geohash.h
     pvt_kf.h
+    receiver_type.h
 )
 
 list(SORT PVT_LIB_HEADERS)
@@ -159,6 +161,16 @@ if(Boost_VERSION_STRING VERSION_LESS 1.71.0)
     )
 endif()
 
+if((CMAKE_CXX_STANDARD AND CMAKE_CXX_STANDARD VERSION_LESS 17) OR
+  (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS "8.0") OR
+  (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS "4.0") OR
+  (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS "10.0"))
+    target_compile_definitions(pvt_libs
+        PUBLIC
+            -DNO_FOLD_EXPRESSIONS=1
+    )
+endif()
+
 set_property(TARGET pvt_libs APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )

src/algorithms/PVT/libs/receiver_type.cc

@@ -33,8 +33,15 @@ Signal_Enabled_Flags::Signal_Enabled_Flags(const ConfigurationInterface* configu
         {BDS_B1, "Channels_B1.count"},
         {BDS_B3, "Channels_B3.count"}};
 
+#if NO_FOLD_EXPRESSIONS
+    for (const auto& pair_aux : signal_flag_to_prop)
+        {
+            auto flag = pair_aux.first;
+            auto prop = pair_aux.second;
+#else
     for (const auto& [flag, prop] : signal_flag_to_prop)
         {
+#endif
             const auto enabled = configuration->property(prop, 0) > 0;
 
             if (enabled)
@@ -44,6 +51,7 @@ Signal_Enabled_Flags::Signal_Enabled_Flags(const ConfigurationInterface* configu
         }
 }
 
+
 uint32_t get_type_of_receiver(const Signal_Enabled_Flags& signal_enabled_flags)
 {
     if (signal_enabled_flags.check_only_enabled(GPS_1C))

src/algorithms/PVT/libs/receiver_type.h

@@ -41,6 +41,31 @@ class Signal_Enabled_Flags
 public:
     explicit Signal_Enabled_Flags(const ConfigurationInterface* configuration);
 
+#if NO_FOLD_EXPRESSIONS
+    template <typename T>
+    uint32_t or_all(const T& value) const
+    {
+        return value;
+    }
+
+    template <typename T, typename... Args>
+    uint32_t or_all(const T& first, const Args&... rest) const
+    {
+        return first | or_all(rest...);
+    }
+
+    template <typename... Args>
+    bool check_only_enabled(const Args&... args) const
+    {
+        return (flags_ ^ or_all(args...)) == 0;
+    }
+
+    template <typename... Args>
+    bool check_any_enabled(const Args&... args) const
+    {
+        return (flags_ & or_all(args...)) > 0;
+    }
+#else
     template <typename... Args>
     bool check_only_enabled(const Args&... args) const
     {
@@ -52,6 +77,7 @@ public:
     {
         return (flags_ & (args | ...)) > 0;
     }
+#endif
 
 private:
     uint32_t flags_;