[Boost-users] Re: Some trouble with "regex_replace()"

From: Arno Schäfer (arno.schaefer_at_[hidden])
Date: 2004-11-10 07:31:08

Ben Hutchings <ben.hutchings <at> businesswebsoftware.com> writes:

> 
> Arno Schäfer wrote:
> > Hi all,
> > 
> > Using "regex_replace(string, pattern, replace_string, flags)" I got some 
> > unwished results. I can't find out what flag set I have to use, that the 
> > replacement string was taken, as it is.
> <snip>
> 
> Post your code.
> 
> Ben.
> 
Here is my test case:

<snip>
#include <iostream>
#define BOOST_NO_WREGEX
#include "boost/regex.hpp"

using namespace std;
using namespace boost;

int main(int argc, char *argv[], char *envp[])
{
    string source_org("My path: '#PATH#'");
    regex pattern("#PATH#");
    string replace("D:\\temp\\rest");
    source_org += " " + source_org;
    bool only_first = false;
    while ( true )
    {
        string source(source_org);
        regex_constants::match_flag_type flags = regex_constants::match_default;
        if ( only_first )
            flags |= regex_constants::format_first_only;
        string result = regex_replace(source, pattern, replace, flags);
        cout << "Pattern \"" << pattern.expression() << "\" in string \"" 
             << source << "\" should be replaced with \"" << replace << "\"" << 
endl
             << "\"" << result << "\"" << endl << endl;

        if ( only_first )
            break;
        only_first = !only_first;
   }
   return 0;
}
Ouput:
Pattern "#PATH#" in string "My path: '#PATH#' My path: '#PATH#'" should be 
replaced with "D:\temp\rest"
est'"My path: 'D:       emp

Pattern "#PATH#" in string "My path: '#PATH#' My path: '#PATH#'" should be 
replaced with "D:\temp\rest"
est' My path: '#PATH#'"

Exspected output:
Pattern "#PATH#" in string "My path: '#PATH#' My path: '#PATH#'" should be 
replaced with "D:\temp\rest"
"My path: 'D:\temp\rest' My path: 'D:\temp\rest'"

Pattern "#PATH#" in string "My path: '#PATH#' My path: '#PATH#'" should be 
replaced with "D:\temp\rest"
"My path: 'D:\temp\rest' My path: '#PATH#'"

<snip>

Arno