[boost] [xpressive] "quantifier not expected" exception when using non-capturing group

From: Jean-Francois Bastien (jfbastien_at_[hidden])
Date: 2007-06-06 06:45:10

Here is a simplification of my expression:
  sregex expression = sregex::compile(
    /* 1 */ "^("
    /* 2 */   "c[^\r\n]*(?:\r?\n|\r)"
    /* 3 */   "(?:"
    /* 4 */     "(?!c)"
   /* 5 */      "[^\r\n]*(?:\r?\n|\r)"
   /* 6 */    ")*"
   /* 7 */  ")"
    );

Basically: match lines starting with a "c" and the line that follow,
until another line starting with a "c" is found.

This gives a "quantifier not expected" exception. Changing line 3 to a
normal group solves the problem. Changing lines 2 and 5's groups to
normal groups also solves the problem.

This expression seems to work fine in PowerGREP.

JF