commit 5f86227e1619f60dadc8a053d14b20338d0fbdac
author William A. Kennington III <wak@google.com> Thu Oct 11 13:55:08 2018 -0700
committer William A. Kennington III <wak@google.com> Fri Oct 12 01:03:47 2018 -0700
tree 2efd99cf37598044b8b3034314bc33c7c7111f1e
parent d5f1d40f2ddf9234099b331e1d90c54ece0ee88b

configure: Update from c++14 to c++17

This uses the AX_CXX_COMPILE_STDCXX() instead of
AX_CXX_COMPILE_STDCXX_1{4,7}() so that the error messages we generate
make slightly more sense.

We get errors like:
configure.ac:24: error: invalid first argument `20' to AX_CXX_COMPILE_STDCXX

Instead of:
./configure: line 5132: syntax error near unexpected token `noext'
./configure: line 5132: `AX_CXX_COMPILE_STDCXX_20(noext)'

Tested:
    Builds and passes unit tests.

Change-Id: I22f71b4f83fec0507de1175ac656ce63e9acecea
Signed-off-by: William A. Kennington III <wak@google.com>

configure.ac

diff --git a/configure.ac b/configure.ac
index e05906f..4613316 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,7 @@
 )
 
 # Checks for typedefs, structures, and compiler characteristics.
-AX_CXX_COMPILE_STDCXX_14([noext])
+AX_CXX_COMPILE_STDCXX(17, [noext], [mandatory])
 AX_APPEND_COMPILE_FLAGS([-fpic -Wall], [CFLAGS])
 AX_APPEND_COMPILE_FLAGS([-fpic -Wall], [CXXFLAGS])