configure.ac: use C++17 for newer Protobufs

intelfx · Sep 27, 2023 · a98e196 · a98e196
1 parent a70c932
commit a98e196
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/configure.ac b/configure.ac
@@ -22,8 +22,12 @@ AS_IF([test x"$PROTOC" = x],
 m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 
 # Protobuf 3.6+ requires C++11.
-AS_IF([pkg-config --atleast-version 3.6.0 protobuf],
-  [AX_CXX_COMPILE_STDCXX([11])])
+# Protobuf 22+ requires C++14 nominally, but building with C++ <17 fails on my machine.
+AS_IF([pkg-config --atleast-version 22.0.0 protobuf],
+      [AX_CXX_COMPILE_STDCXX([17])],
+      [pkg-config --atleast-version 3.6.0 protobuf],
+      [AX_CXX_COMPILE_STDCXX([11])]
+     )
 
 WARNING_CXXFLAGS=""
 PICKY_CXXFLAGS=""