Compile error in latest repository tip

[Daniel J Sebald]

I've cloned a fresh version of the repository, bootstrapped, and run 
make to get the following error:

  CXX 
libinterp/dldfcn/libinterp_dldfcn___delaunayn___la-__delaunayn__.lo
In file included from 
/home/sebald/octave/octave/octave/liboctave/array/Array.h:38:0,
                 from 
/home/sebald/octave/octave/octave/libinterp/corefcn/Cell.h:31,
                 from 
/home/sebald/octave/octave/octave/libinterp/dldfcn/__delaunayn__.cc:50:
/home/sebald/octave/octave/octave/liboctave/array/idx-vector.h:68:55: 
error: 'unique_ptr' in namespace 'std' does not name a type
In file included from 
/home/sebald/octave/octave/octave/libinterp/dldfcn/__delaunayn__.cc:55:0:
/home/sebald/octave/octave/octave/liboctave/util/unwind-prot.h: In 
member function 'virtual void unwind_protect::run_first()':
/home/sebald/octave/octave/octave/liboctave/util/unwind-prot.h:71:9: 
error: 'unique_ptr' is not a member of 'std'
/home/sebald/octave/octave/octave/liboctave/util/unwind-prot.h:71:29: 
error: expected primary-expression before '>' token
/home/sebald/octave/octave/octave/liboctave/util/unwind-prot.h:71:47: 
error: 'ptr' was not declared in this scope
/home/sebald/octave/octave/octave/libinterp/dldfcn/__delaunayn__.cc: In 
function 'octave_value_list F__delaunayn__(const octave_value_list&, int)':
/home/sebald/octave/octave/octave/libinterp/dldfcn/__delaunayn__.cc:194:19: 
warning: use of old-style cast
make[2]: *** 
[libinterp/dldfcn/libinterp_dldfcn___delaunayn___la-__delaunayn__.lo] 
Error 1
make[2]: Leaving directory `/usr/local/src/octave/octave/build7'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/local/src/octave/octave/build7'
make: *** [all] Error 2

Dan