Switch to C++17

There is no harm in doing this since we are not a client library and all
environments using this project should have c++17 compliant compilers at
this point.

Tested:
    Run through unit test suite.

Change-Id: Iceae5375fd69b1929e1c4e2c6c297d131c61de68
Signed-off-by: William A. Kennington III <wak@google.com>

3 files changed, 10 insertions, 9 deletions

diff --git a/configure.ac b/configure.ac
index a911296..6c5ac70 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,7 +12,7 @@ AC_PROG_CXX
 AC_PROG_INSTALL
 
 # Checks for typedefs, structures, and compiler characteristics.
-AX_CXX_COMPILE_STDCXX_14([noext])
+AX_CXX_COMPILE_STDCXX([17], [noext], [mandatory])
 AX_APPEND_COMPILE_FLAGS([-Wall -Werror], [CXXFLAGS])
 
 # For linking
diff --git a/mainapp.cpp b/mainapp.cpp
index 889e241..72277d1 100644
--- a/mainapp.cpp
+++ b/mainapp.cpp
@@ -17,8 +17,8 @@
 #include "argument.hpp"
 #include "watchdog.hpp"
 
-#include <experimental/optional>
 #include <iostream>
+#include <optional>
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/log.hpp>
@@ -149,7 +149,7 @@ int main(int argc, char** argv)
     {
         exitWithError("Multiple fallbacks specified.", argv);
     }
-    std::experimental::optional<Watchdog::Fallback> fallback;
+    std::optional<Watchdog::Fallback> fallback;
     if (!fallbackActionParam.empty())
     {
         Watchdog::Action action;
diff --git a/watchdog.hpp b/watchdog.hpp
index ea419e7..efa413a 100644
--- a/watchdog.hpp
+++ b/watchdog.hpp
@@ -2,12 +2,14 @@
 
 #include "timer.hpp"
 
-#include <systemd/sd-event.h>
-
-#include <experimental/optional>
+#include <functional>
+#include <map>
+#include <optional>
 #include <sdbusplus/bus.hpp>
 #include <sdbusplus/server/object.hpp>
+#include <utility>
 #include <xyz/openbmc_project/State/Watchdog/server.hpp>
+
 namespace phosphor
 {
 namespace watchdog
@@ -54,8 +56,7 @@ class Watchdog : public WatchdogInherits
     Watchdog(sdbusplus::bus::bus& bus, const char* objPath, EventPtr& event,
              std::map<Action, TargetName>&& actionTargets =
                  std::map<Action, TargetName>(),
-             std::experimental::optional<Fallback>&& fallback =
-                 std::experimental::nullopt) :
+             std::optional<Fallback>&& fallback = std::nullopt) :
         WatchdogInherits(bus, objPath),
         bus(bus), actionTargets(std::move(actionTargets)),
         fallback(std::move(fallback)),
@@ -129,7 +130,7 @@ class Watchdog : public WatchdogInherits
     std::map<Action, TargetName> actionTargets;
 
     /** @brief Fallback timer options */
-    std::experimental::optional<Fallback> fallback;
+    std::optional<Fallback> fallback;
 
     /** @brief Contained timer object */
     Timer timer;