Glib::ustring conversion

[Arthur <arthurmaciel gmail com>]

Hi there.

I'm building a simple calculator with Glade(mm) and I would like to know 
if it is possible to convert Glib::ustring to double and then double to 
Glib::ustring.
I need this because the calculator has an entrytext widget and when I 
press the numbers and signs (plus, minus, multiply, divide, left 
parenthesis and right parenthesis) a string is shown at this entry text: 
"1254 + 13241 - (13241 * 1341)". When the equal button (=) is pressed I 
want to pass this string as a double and make C++ to solve this 
mathematic expression for me and return the result, so I can set it as 
the entry text string again.

If anyone could help me, I would appreciate.

Regards,

Arthur