$ perl5.12.2 junk
Compiling REx "-?\p{Nd}"
synthetic stclass "ANYOF[\-][+utf8::Nd]".
Final program:
   1: CURLY {0,1} (5)
   3:   EXACT <-> (0)
   5: ANYOF[{unicode}+utf8::Nd] (17)
  17: END (0)
stclass ANYOF[\-][+utf8::Nd] minlen 1
Matching REx "-?\p{Nd}" against "1"
Matching stclass ANYOF[\-][+utf8::Nd] against "1" (1 chars)
Contradicts stclass... [regexec_flags]
Match failed
Doesn't match
Freeing REx: "-?\p{Nd}"