Re: [Boost-users] [regex] match_results: signatures of position(sub) and length(sub) are different, why?

It's historical: length() can be used with the "special" values -1 and -2 to obtain the length of prefix() and suffix(), that's deprecated, and I don't *think* it's documented anywhere anymore, but was retained for backwards compatibility.

I guess after all this time it could be changed now, but I don't see it's causing any great harm either,

I see that the standard says: difference_type length(size_type sub = 0) const; difference_type position(size_type sub = 0) const; Frédéric