xapian-letor

In file included from /usr/include/xapian.h:43:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/types.h:25:3: error: #error "Never use <xapian/types.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/types.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/types.h:28:0,
                 from /usr/include/xapian.h:43,
                 from xapian-rank.cc:23:
/usr/include/xapian/deprecated.h:24:3: error: #error "Never use <xapian/deprecated.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/deprecated.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:46:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/error.h:27:3: error: #error "Never use <xapian/error.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/error.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:47:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/errorhandler.h:25:3: error: #error "Never use <xapian/errorhandler.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/errorhandler.h> directly; include <xapian.h> instead
   ^
In file included from /usr/include/xapian/errorhandler.h:30:0,
                 from /usr/include/xapian.h:47,
                 from xapian-rank.cc:23:
/usr/include/xapian/intrusive_ptr.h:40:3: error: #error "Never use <xapian/intrusive_ptr.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/intrusive_ptr.h> directly; include <xapian.h> instea
   ^
In file included from /usr/include/xapian.h:50:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/database.h:29:3: error: #error "Never use <xapian/database.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/database.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/database.h:40:0,
                 from /usr/include/xapian.h:50,
                 from xapian-rank.cc:23:
/usr/include/xapian/positioniterator.h:26:3: error: #error "Never use <xapian/positioniterator.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/positioniterator.h> directly; include <xapian.h> ins
   ^
In file included from /usr/include/xapian/positioniterator.h:33:0,
                 from /usr/include/xapian/database.h:40,
                 from /usr/include/xapian.h:50,
                 from xapian-rank.cc:23:
/usr/include/xapian/derefwrapper.h:26:3: error: #error "Never use <xapian/derefwraper.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/derefwraper.h> directly; include <xapian.h> instead.
   ^
In file included from /usr/include/xapian/database.h:41:0,
                 from /usr/include/xapian.h:50,
                 from xapian-rank.cc:23:
/usr/include/xapian/postingiterator.h:26:3: error: #error "Never use <xapian/postingiterator.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/postingiterator.h> directly; include <xapian.h> inst
   ^
In file included from /usr/include/xapian/database.h:42:0,
                 from /usr/include/xapian.h:50,
                 from xapian-rank.cc:23:
/usr/include/xapian/termiterator.h:26:3: error: #error "Never use <xapian/termiterator.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/termiterator.h> directly; include <xapian.h> instead
   ^
In file included from /usr/include/xapian/database.h:43:0,
                 from /usr/include/xapian.h:50,
                 from xapian-rank.cc:23:
/usr/include/xapian/valueiterator.h:26:3: error: #error "Never use <xapian/valueiterator.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/valueiterator.h> directly; include <xapian.h> instea
   ^
In file included from /usr/include/xapian.h:51:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/dbfactory.h:26:3: error: #error "Never use <xapian/dbfactory.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/dbfactory.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/dbfactory.h:31:0,
                 from /usr/include/xapian.h:51,
                 from xapian-rank.cc:23:
/usr/include/xapian/constants.h:26:3: error: #error "Never use <xapian/constants.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/constants.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:52:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/document.h:29:3: error: #error "Never use <xapian/document.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/document.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:59:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/termgenerator.h:25:3: error: #error "Never use <xapian/termgenerator.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/termgenerator.h> directly; include <xapian.h> instea
   ^
In file included from /usr/include/xapian/termgenerator.h:30:0,
                 from /usr/include/xapian.h:59,
                 from xapian-rank.cc:23:
/usr/include/xapian/unicode.h:25:3: error: #error "Never use <xapian/unicode.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/unicode.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:62:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/enquire.h:30:3: error: #error "Never use <xapian/enquire.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/enquire.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/enquire.h:37:0,
                 from /usr/include/xapian.h:62,
                 from xapian-rank.cc:23:
/usr/include/xapian/eset.h:26:3: error: #error "Never use <xapian/eset.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/eset.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/eset.h:34:0,
                 from /usr/include/xapian/enquire.h:37,
                 from /usr/include/xapian.h:62,
                 from xapian-rank.cc:23:
/usr/include/xapian/stem.h:26:3: error: #error "Never use <xapian/stem.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/stem.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/enquire.h:39:0,
                 from /usr/include/xapian.h:62,
                 from xapian-rank.cc:23:
/usr/include/xapian/mset.h:26:3: error: #error "Never use <xapian/mset.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/mset.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:63:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/expanddecider.h:25:3: error: #error "Never use <xapian/expanddecider.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/expanddecider.h> directly; include <xapian.h> instea
   ^
In file included from /usr/include/xapian.h:64:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/keymaker.h:26:3: error: #error "Never use <xapian/keymaker.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/keymaker.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:65:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/matchspy.h:27:3: error: #error "Never use <xapian/matchspy.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/matchspy.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:66:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/postingsource.h:26:3: error: #error "Never use <xapian/postingsource.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/postingsource.h> directly; include <xapian.h> instea
   ^
In file included from /usr/include/xapian.h:67:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/query.h:26:3: error: #error "Never use <xapian/query.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/query.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian/query.h:34:0,
                 from /usr/include/xapian.h:67,
                 from xapian-rank.cc:23:
/usr/include/xapian/registry.h:27:3: error: #error "Never use <xapian/registry.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/registry.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:68:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/queryparser.h:27:3: error: #error "Never use <xapian/queryparser.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/queryparser.h> directly; include <xapian.h> instead.
   ^
In file included from /usr/include/c++/5/unordered_set:35:0,
                 from /usr/include/xapian/queryparser.h:37,
                 from /usr/include/xapian.h:68,
                 from xapian-rank.cc:23:
/usr/include/c++/5/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
 #error This file requires compiler and library support \
  ^
In file included from /usr/include/xapian.h:69:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/valuesetmatchdecider.h:27:3: error: #error "Never use <xapian/valuesetmatchdecider.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/valuesetmatchdecider.h> directly; include <xapian.h>
   ^
In file included from /usr/include/xapian.h:82:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/compactor.h:27:3: error: #error "Never use <xapian/compactor.h> directly; include <xapian.h> instead."
 # error "Never use <xapian/compactor.h> directly; include <xapian.h> instead."
   ^
In file included from /usr/include/xapian.h:68:0,
                 from xapian-rank.cc:23:
/usr/include/xapian/queryparser.h:96:10: error: ‘unordered_set’ in namespace ‘std’ does not name a template type
     std::unordered_set<std::string> stop_words;
          ^
/usr/include/xapian/queryparser.h: In constructor ‘Xapian::SimpleStopper::SimpleStopper(Iterator, Iterator)’:
/usr/include/xapian/queryparser.h:112:51: error: class ‘Xapian::SimpleStopper’ does not have any field named ‘stop_words’
     SimpleStopper(Iterator begin, Iterator end) : stop_words(begin, end) { }
                                                   ^
/usr/include/xapian/queryparser.h: In member function ‘void Xapian::SimpleStopper::add(const string&)’:
/usr/include/xapian/queryparser.h:115:42: error: ‘stop_words’ was not declared in this scope
     void add(const std::string & word) { stop_words.insert(word); }
                                          ^
/usr/include/xapian/queryparser.h: In member function ‘virtual bool Xapian::SimpleStopper::operator()(const string&) const’:
/usr/include/xapian/queryparser.h:118:9: error: ‘stop_words’ was not declared in this scope
  return stop_words.find(term) != stop_words.end();