build: migrate to C++17

Change-Id: Ic5c01274f62556764ea96fc232cf3d835c4ab659
diff --git a/.waf-tools/default-compiler-flags.py b/.waf-tools/default-compiler-flags.py
index f086c17..7c6d282 100644
--- a/.waf-tools/default-compiler-flags.py
+++ b/.waf-tools/default-compiler-flags.py
@@ -136,7 +136,7 @@
     """
     def getGeneralFlags(self, conf):
         flags = super(GccBasicFlags, self).getGeneralFlags(conf)
-        flags['CXXFLAGS'] += ['-std=c++14']
+        flags['CXXFLAGS'] += ['-std=c++17']
         if Utils.unversioned_sys_platform() == 'linux':
             flags['LINKFLAGS'] += ['-fuse-ld=gold']
         elif Utils.unversioned_sys_platform() == 'freebsd':