Wt

The preview verson of wt4, github 3.3.6-17-gfd7099d7, gets compilation errors on DboTest3.C with g (Debian 6.2.1-5) 6.2.1 20161124 under Debian stretch (testing). Here is one of the reported errors (with abbreviated paths):

In file included from /x/boost/boost_1_62/include/boost-1_62/boost/test/test_tools.hpp:45:0,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/unit_test.hpp:18,
                 from /x/wt4p/test/dbo/DboTest3.C:7:
/x/wt4p/test/dbo/DboTest3.C: In member function ‘void dbo3_test2::test_method()’:
/x/wt4p/test/dbo/DboTest3.C:145:49: error: call of overloaded ‘abs(std::__tuple_element_t<1ul, std::tuple<int, double> >)’ is ambiguous
   BOOST_REQUIRE(std::abs(std::get<1>(tupe) - 6.6) < 0.001);
                                                 ^
/x/boost/boost_1_62/include/boost-1_62/boost/test/tools/old/interface.hpp:49:47: note: in definition of macro ‘BOOST_TEST_TOOL_PASS_PRED2’
 #define BOOST_TEST_TOOL_PASS_PRED2( P, ARGS ) P
                                               ^
/x/boost/boost_1_62/include/boost-1_62/boost/test/tools/old/interface.hpp:82:45: note: in expansion of macro ‘BOOST_TEST_TOOL_IMPL’
 #define BOOST_REQUIRE( P )                  BOOST_TEST_TOOL_IMPL( 2, \
                                             ^~~~~~~~~~~~~~~~~~~~
/x/wt4p/test/dbo/DboTest3.C:145:3: note: in expansion of macro ‘BOOST_REQUIRE’
   BOOST_REQUIRE(std::abs(std::get<1>(tupe) - 6.6) < 0.001);
   ^~~~~~~~~~~~~
In file included from /x/boost/boost_1_62/include/boost-1_62/boost/config/platform/linux.hpp:15:0,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/config.hpp:57,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/test_tools.hpp:17,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/unit_test.hpp:18,
                 from /x/wt4p/test/dbo/DboTest3.C:7:
/usr/include/c++/6/cstdlib:172:3: note: candidate: long int std::abs(long int)
   abs(long __i) { return __builtin_labs(__i); }
   ^~~
In file included from /usr/include/c++/6/cstdlib:75:0,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/config/platform/linux.hpp:15,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/config.hpp:57,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/test_tools.hpp:17,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/unit_test.hpp:18,
                 from /x/wt4p/test/dbo/DboTest3.C:7:
/usr/include/stdlib.h:735:12: note: candidate: int abs(int)
 extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur;
            ^~~
In file included from /x/boost/boost_1_62/include/boost-1_62/boost/config/platform/linux.hpp:15:0,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/config.hpp:57,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/test_tools.hpp:17,
                 from /x/boost/boost_1_62/include/boost-1_62/boost/test/unit_test.hpp:18,
                 from /x/wt4p/test/dbo/DboTest3.C:7:
/usr/include/c++/6/cstdlib:180:3: note: candidate: long long int std::abs(long long int)
   abs(long long __x) { return __builtin_llabs (__x); }
   ^~~

I believe the issue can be addressed by adding an include for cmath. A trivial patch is attached.