gmp ptrdiff errors

In file included from t-cast.cc:20:
In file included from ../../gmp.h:51:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/cstddef:51:9: error: no member named 'ptrdiff_t' in the global namespace
using ::ptrdiff_t;
      ~~^
In file included from t-cast.cc:21:
In file included from ../../gmpxx.h:29:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/algorithm:594:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:596:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iterator:386:13: error: unknown type name 'ptrdiff_t'
    typedef ptrdiff_t difference_type;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iterator:413:56: error: unknown type name 'ptrdiff_t'
template<class _Category, class _Tp, class _Distance = ptrdiff_t,
                                                       ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iterator:720:66: error: unknown type name 'ptrdiff_t'
          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
                                                                 ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iterator:720:54: error: template parameter missing a default argument
          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
                                                     ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iterator:720:27: note: previous default template argument defined here
          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
                          ^
In file included from t-cast.cc:21:
In file included from ../../gmpxx.h:29:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/algorithm:594:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:794:13: error: unknown type name 'ptrdiff_t'
    typedef ptrdiff_t type;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:942:13: error: unknown type name 'ptrdiff_t'
    typedef ptrdiff_t difference_type;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1561:13: error: unknown type name 'ptrdiff_t'
            ptrdiff_t _Np = __end1 - __begin1;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1591:13: error: unknown type name 'ptrdiff_t'
            ptrdiff_t _Np = __end1 - __begin1;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1655:13: error: unknown type name 'ptrdiff_t'
    typedef ptrdiff_t         difference_type;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1747:13: error: unknown type name 'ptrdiff_t'
    typedef ptrdiff_t         difference_type;
            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1844:23: error: use of undeclared identifier 'ptrdiff_t'
                      ptrdiff_t,                                   // purposefully not C++03
                      ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1846:65: error: expected class name
                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
                                                                ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1861:12: error: use of undeclared identifier 'ptrdiff_t'
pair<_Tp*, ptrdiff_t>
           ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1862:22: error: unknown type name 'ptrdiff_t'
get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
                     ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1864:16: error: use of undeclared identifier 'ptrdiff_t'
    pair<_Tp*, ptrdiff_t> __r(0, 0);
               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1865:11: error: unknown type name 'ptrdiff_t'
    const ptrdiff_t __m = (~ptrdiff_t(0) ^
          ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1865:29: error: use of undeclared identifier 'ptrdiff_t'
    const ptrdiff_t __m = (~ptrdiff_t(0) ^
                            ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/memory:1866:38: error: use of undeclared identifier 'ptrdiff_t'
                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
                                     ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
make[4]: *** [t-cast.o] Error 1
make[3]: *** [check-am] Error 2
make[2]: *** [check-recursive] Error 1
make[1]: *** [check-recursive] Error 1
make: *** [check] Error 2