Re: [Boost-users] A problem with '^' and '$' in boost regex

Alan Huang wrote:

Hi,

In boost document I saw that the '^' matches all the blank chars in the begin of line and the '$' matches all the blank chars in the end of line. Just like regex( "^abc$" ) can't match the string " abc ". What's wrong?

You misunderstood. ^ doesn't match any characters, it simply fails if it's not the start of the line. In other words, it says, "The expression after me must match at the start of the line, not simply somewhere." $ does the same for the end of the line. Therefore, "^cde" matches "cdefg", but not "abcde". If the boost documentation really says that ^ and $ match any blank chars, that's a bug and should be corrected. Sebastian Redl