search for: n1969

...t; Their guidance for maximum > object size is stated to be half of SIZE_MAX in C11 K.3.4/4 which is > typically equivalent to PTRDIFF_MAX. Whose guidance? Annex K is kinda alien to the rest of the standard and its future is not clear. See, e.g., http://open-std.org/jtc1/sc22/wg14/www/docs/n1969.htm . > - The expectation that PTRDIFF_MAX is more or less a proxy for the largest > object size is not uncommon. For example, C++'s std::count doesn't return > a size_t but a iterator_traits<>::difference_type which is going to be a > ptrdiff_t for things like std::vec...

I've come across this issue before and came to the following conclusion: - We are not obligated to support objects that large, C11 5.2.4.1/1 only requires that we support objects of size 65535! Their guidance for maximum object size is stated to be half of SIZE_MAX in C11 K.3.4/4 which is typically equivalent to PTRDIFF_MAX. - The expectation that PTRDIFF_MAX is more or less a proxy for the

It could be that 32-bit systems are disappearing so rapidly that nobody cares too much about this issue, but this blog post is still worth reading: http://trust-in-soft.com/objects-larger-than-ptrdiff_max-bytes/ John

...> object size is stated to be half of SIZE_MAX in C11 K.3.4/4 which is >> typically equivalent to PTRDIFF_MAX. >> > > Whose guidance? Annex K is kinda alien to the rest of the standard and its > future is not clear. See, e.g., > http://open-std.org/jtc1/sc22/wg14/www/docs/n1969.htm . That document objects to much of Annex K but doesn't say anything about K.3.4/4. > > > - The expectation that PTRDIFF_MAX is more or less a proxy for the largest >> object size is not uncommon. For example, C++'s std::count doesn't >> return >> a s...