New autoconf bitfcns test failing

[Rik]

6/5/12

Carlo,

In the following changeset you added autoconf checking for templated bit
functions like bit_and, bit_or, and bit_xor.

changeset:   14725:fa48fd0f160f
user:        Carlo de Falco <address@hidden>
date:        Tue Jun 05 07:39:46 2012 +0200
summary:     Add configure check for templated bitwise operators.

Unfortunately, I now can't compile on a straight Linux distribution (Ubuntu
10.04).  I get the following errors when trying to compile src/bitfcns.cc

bitfcns.cc:51: error: redefinition of ‘struct std::bit_and<_Tp>’
/usr/include/c++/4.4/bits/stl_function.h:293: error: previous definition of
‘struct std::bit_and<_Tp>’
bitfcns.cc:58: error: redefinition of ‘struct std::bit_or<_Tp>’
/usr/include/c++/4.4/bits/stl_function.h:301: error: previous definition of
‘struct std::bit_or<_Tp>’
bitfcns.cc:65: error: redefinition of ‘struct std::bit_xor<_Tp>’
/usr/include/c++/4.4/bits/stl_function.h:309: error: previous definition of
‘struct std::bit_xor<_Tp>’
make[3]: *** [liboctinterp_la-bitfcns.lo] Error 1

If I look at config.h it shows that HAVE_CXX_BITWISE_OP_TEMPLATES is
undefined so the templates get re-defined at the start of bitfcns.cc.  It
looks like it must be something with the test program in acinclude.m4 which
is returning the wrong result.

--Rik