are C functions declared in headers guaranteed to be in the global namespace as well as std?

Question

So this is something that I\'ve always wondered but was never quite sure about. So it is strictly a matter of curiosity, not a real problem.

As far as I understand,

Answer 1

Here's a nice synopsis of the situation (with some relaity vs. what the standard says) from Stephan T. Lavavej of the MSVC team (http://blogs.msdn.com/vcblog/archive/2008/08/28/the-mallocator.aspx#8904359):

> also, , , and std::size_t etc should be used!

I used to be very careful about that. C++98 had a splendid dream wherein would declare everything within namespace std, and would include and then drag everything into the global namespace with using-declarations. (This is D.5 [depr.c.headers].)

This was ignored by lots of implementers (some of which had very little control over the C Standard Library headers). So, C++0x has been changed to match reality. As of the N2723 Working Paper, http://open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf , now is guaranteed to declare everything within namespace std, and may or may not declare things within the global namespace. is the opposite: it is guaranteed to declare everything within the global namespace, and may or may not declare things within namespace std.

In reality and in C++0x, including is no safeguard against everything getting declared in the global namespace anyways. That's why I'm ceasing to bother with .

This was Library Issue 456, http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#456 .

(C++0x still deprecates the headers from the C Standard Library, which is hilarious.)

I've never been fond of the headers myself, and found that I've always use . Now I feel like I can stop being anxious about my lack of C++ 'purity' in that regard.