Someone

#include "ini.h"

namespace figconfig
{
    regex letter = range('a','z')|range('A','Z');
    regex number = range('0','9');
    regex underscore = term('_');
    regex identifier = +(letter|number|underscore);
    regex strchars = range(' ','!')|range('#','~');
    regex RxString = term('"') >> *strchars >> term('"');
    regex value = RxString|identifier;
    regex key = term('[') >> identifier >> term(']') >> term('\n');
    regex assign = identifier >> term('=') >> value >> term('\n');
}