You may find this table useful:
http://www.codeguru.com/dbfiles/get_image.php?id=16465&lbl=01-BIG_PNG&ds=20091012
from this interesting and concise article:
"About size_t and ptrdiff_t"
http://www.codeguru.com/cpp/cpp/cpp_mfc/general/article.php/c16465
Luis