$ 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}"

##</code><code>##

$ perl5.14.1 junk
Compiling REx "-?\p{Nd}"
synthetic stclass "ANYOF{i}[\-][{non-utf8-latin1-all}{unicode}{outside bitmap}+utf8::Nd]".
Final program:
   1: CURLY {0,1} (5)
   3:   EXACT <-> (0)
   5: ANYOF[{unicode}{outside bitmap}+utf8::Nd] (16)
  16: END (0)
stclass ANYOF{i}[\-][{non-utf8-latin1-all}{unicode}{outside bitmap}+utf8::Nd] minlen 1
Matching REx "-?\p{Nd}" against "1"
Matching stclass ANYOF{i}[\-][{non-utf8-latin1-all}{unicode}{outside bitmap}+utf8::Nd] against "1" (1 bytes)
   0 <> <1>                  |  1:CURLY {0,1}(5)
                                  EXACT <-> can match 0 times out of 1...
   0 <> <1>                  |  5:  ANYOF[{unicode}{outside bitmap}0-9...+utf8::Nd](16)
   1 <1> <>                  | 16:  END(0)
Match successful!
Matches
Freeing REx: "-?\p{Nd}"

##</code><code>##


$ perl5.12.2 junk
Compiling REx "-?\p{Nd}{1}"
Final program:
   1: CURLY {0,1} (5)
   3:   EXACT <-> (0)
   5: CURLY {1,1} (19)
   7:   ANYOF[{unicode}+utf8::Nd] (0)
  19: END (0)
minlen 1
Matching REx "-?\p{Nd}{1}" against "1"
   0 <> <1>                  |  1:CURLY {0,1}(5)
                                  EXACT <-> can match 0 times out of 1...
   0 <> <1>                  |  5:  CURLY {1,1}(19)
                                    ANYOF[{unicode}0-9...+utf8::Nd] can match 1 times out of 1...
   1 <1> <>                  | 19:    END(0)
Match successful!
Matches
Freeing REx: "-?\p{Nd}{1}"

##</code><code>##

$ perl5.14.1 junk
Compiling REx "-?\p{Nd}{1}"
Final program:
   1: CURLY {0,1} (5)
   3:   EXACT <-> (0)
   5: CURLY {1,1} (18)
   7:   ANYOF[{unicode}{outside bitmap}+utf8::Nd] (0)
  18: END (0)
minlen 1
Matching REx "-?\p{Nd}{1}" against "1"
   0 <> <1>                  |  1:CURLY {0,1}(5)
                                  EXACT <-> can match 0 times out of 1...
   0 <> <1>                  |  5:  CURLY {1,1}(18)
                                    ANYOF[{unicode}{outside bitmap}0-9...+utf8::Nd] can match 1 times out of 1...
   1 <1> <>                  | 18:    END(0)
Match successful!
Matches
Freeing REx: "-?\p{Nd}{1}"