Hi, With regards to the following lines in the latest version (1.16) of program_options's options_description.cpp: 395: line_end = line_begin + line_length; 396: if (line_end > par_end) 397: { 398: line_end = par_end; 399: } Line 395 causes VC8 to throw a runtime assertion error when processing the last line of a multiline option description. This is because 'line_begin + line_length' will exceed the actual length of the string, and it seems VC8 is pretty intent on not letting that happen, despite the fact we correct it in following line. Following patch did the trick for me: --- options_description-1.16.cpp 2006-04-18 02:39:51.401147200 +0100 +++ options_description.cpp 2006-04-18 03:04:05.722358400 +0100 @@ -390,13 +390,13 @@ } } - string::const_iterator line_end; + string::const_iterator line_end = line_begin; + unsigned remaining = unsigned(distance(line_begin, par_end)); - line_end = line_begin + line_length; - if (line_end > par_end) - { - line_end = par_end; - } + // line_end will be determined by either the end of the + // current paragraph (remaining), or the current line + // length, which ever is less. + line_end += ((remaining < line_length) ? remaining : line_length); // prevent chopped words // Is line_end between two non-space characters?