From 4c718643195216c1e56d0db4ab6bf13584a24086 Mon Sep 17 00:00:00 2001
From: Carles Fernandez <carles.fernandez@gmail.com>
Date: Sat, 16 Mar 2019 20:30:38 +0100
Subject: [PATCH] Fix for gcc < 5.0

---
 src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt   | 12 ++++++++++++
 src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc |  4 ++++
 2 files changed, 16 insertions(+)

diff --git a/src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt b/src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt
index 936f4c05f..69dd5c022 100644
--- a/src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt
+++ b/src/algorithms/PVT/gnuradio_blocks/CMakeLists.txt
@@ -58,6 +58,18 @@ if(Boost_VERSION LESS 105800)
     target_compile_definitions(pvt_gr_blocks PRIVATE -DOLD_BOOST=1)
 endif()
 
+# Check if we have std::put_time (Workaround for gcc < 5.0)
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("
+    #include <iomanip>
+    int main()
+    { std::put_time(nullptr, \"\"); }"
+    HAS_PUT_TIME
+)
+if(${HAS_PUT_TIME})
+    target_compile_definitions(pvt_gr_blocks PRIVATE -DHAS_PUT_TIME=1)
+endif()
+
 set_property(TARGET pvt_gr_blocks
     APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
diff --git a/src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc b/src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc
index 09e49a576..22915cca5 100644
--- a/src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc
+++ b/src/algorithms/PVT/gnuradio_blocks/rtklib_pvt_gs.cc
@@ -369,7 +369,9 @@ rtklib_pvt_gs::rtklib_pvt_gs(uint32_t nchannels,
     time_t when = std::time(nullptr);
     auto const tm = *std::localtime(&when);
     std::ostringstream os;
+#ifdef HAS_PUT_TIME
     os << std::put_time(&tm, "%z");
+#endif
     std::string utc_diff_str = os.str();  // in ISO 8601 format: "+HHMM" or "-HHMM"
     if (utc_diff_str.empty())
         {
@@ -379,7 +381,9 @@ rtklib_pvt_gs::rtklib_pvt_gs(uint32_t nchannels,
     int m = std::stoi(utc_diff_str[0] + utc_diff_str.substr(3), nullptr, 10);
     d_utc_diff_time = boost::posix_time::hours(h) + boost::posix_time::minutes(m);
     std::ostringstream os2;
+#ifdef HAS_PUT_TIME
     os2 << std::put_time(&tm, "%Z");
+#endif
     std::string time_zone_abrv = os2.str();
     if (time_zone_abrv.empty())
         {