Thorsten Ottosen wrote:

The xpressive docs say

sregex rex = sregex::compile( "(\\w+) (\\w+)!" );

can be expressed as

sregex rex = (s1= +_w) >> ' ' >> (s2= +_w) >> '!';

. Shouldn't this be

sregex rex = +_w >> ' ' >> +_w >> '!';

since you don't need to refer to previous matches?

The point the doc is making is that the two expressions are equivalent. Without the captures, the second regex doesn't do exactly what the first one does. For instance, when written the first way, the resulting match_results will have saved sub_matches 1 and 2, whereas the second one will not. HTH -- Eric Niebler Boost Consulting www.boost-consulting.com