------- Comment #16 from mdorey at bluearc dot com 2009-12-22 18:12 ------- (In reply to comment #15) > you missed the part where I said "but 0 is still a valid definition of NULL"
(I didn't quote it but I did explicitly agree with it.) > You claimed in comment 12 that the compiler will be *required* to reject > conversions from NULL to int, which is patently not true if 0 or 0L is a valid > definition of NULL. You're right. My citations in comment #9 refer to nullptr, not NULL, and my examples in comment #12 refer to __null, not NULL. In my prose for comment #12, however, I was wrongly assuming that NULL would be required to be nullptr in the new Standard. Having read more of the current draft in response to your post of yesterday, I agree that such a change is not required. This PR, then, is not an accepts-invalid. It's an enhancement request to reinstate one of the warnings, about accidentally inappropriate use of NULL, that became disabled by default between gcc-4.1 and gcc-4.2. Three warnings about NULL conversions were disabled by default in 4.2. Per comment #1, this was because two of the warnings rejected code which ought to be allowed. Per comment #9, that code which ought to be allowed is a valid use of nullptr. However, 4.3 seems to have removed the two problematic warnings, even when -Wconversion is used. That suggests that this PR could now be addressed, without regressing the two PRs cited in comment #1, by enabling the warning about this particular conversion by default, as it was in 4.1. That would address the OP's example and discourage code that wouldn't compile with #define NULL nullptr. Evidence for the new claim in the above paragraph: mart...@ithaki:~/playpen$ g++-4.1 -c -pedantic null-conversion.cpp null-conversion.cpp: In function void test(): null-conversion.cpp:2: warning: converting to non-pointer type bool from NULL null-conversion.cpp:3: warning: converting to non-pointer type int from NULL null-conversion.cpp:4: warning: converting to non-pointer type int from NULL mart...@ithaki:~/playpen$ mart...@duezer:~/playpen$ g++-4.2 -c -pedantic null-conversion.cpp mart...@duezer:~/playpen$ g++-4.2 -Wconversion -c -pedantic null-conversion.cpp null-conversion.cpp: In function void test(): null-conversion.cpp:2: warning: converting to non-pointer type bool from NULL null-conversion.cpp:3: warning: converting to non-pointer type int from NULL null-conversion.cpp:4: warning: converting to non-pointer type int from NULL mart...@duezer:~/playpen$ mart...@duezer:~/playpen$ g++-4.3 -c -pedantic null-conversion.cpp mart...@duezer:~/playpen$ g++-4.3 -Wconversion -c -pedantic null-conversion.cpp null-conversion.cpp: In function void test(): null-conversion.cpp:3: warning: converting to non-pointer type int from NULL mart...@duezer:~/playpen$ -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35669
