[Bug c++/47729] New: Failure to receive warning message when comparing signed and unsigned integers
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47729 Summary: Failure to receive warning message when comparing signed and unsigned integers Product: gcc Version: unknown Status: UNCONFIRMED Severity: major Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: samuelma...@gmail.com Created attachment 2 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=2 Commented test-case with example prominently shown Unfortunately I don't receive warning message when comparing signed and unsigned integers within a function. When comparing with >, >=, < or <=, it gives me a warning message. Only when comparing with != inside a function does the warning message not appear. Please fix this bug. Thank you, Samuel Marks
[Bug c++/47729] Failure to receive warning message when comparing signed and unsigned integers
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47729 Samuel Marks changed: What|Removed |Added Severity|normal |major --- Comment #2 from Samuel Marks 2011-02-14 11:19:29 UTC --- (In reply to comment #1) > > Unfortunately I don't receive warning message when comparing signed and > > unsigned integers within a function. > > > > When comparing with >, >=, < or <=, it gives me a warning message. > > > > Only when comparing with != inside a function does the warning message not > > appear. > > This is rather confused. You don't get the warning on line 19 because the > function template is instantiated with n/size equal to the constant 4u, so > there is no real need to warn here. > > The relevant comment in the source code of the compiler is: > > /* Do not warn if the comparison is an equality operation, the > unsigned quantity is an integral constant, and it would fit > in the result if the result were signed. */ Good point, I was thinking the same; however thought that condition would also hold true for >, <, >=, <=...
[Bug c++/47729] Failure to receive warning message when comparing signed and unsigned integers
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47729 Samuel Marks changed: What|Removed |Added Status|RESOLVED|UNCONFIRMED Resolution|WONTFIX | --- Comment #4 from Samuel Marks 2011-02-14 16:47:42 UTC --- Since comparison between any boolean expression, not just != is valid for any types, why have any warns at all? Otherwise, have warns for every boolean equality expression.
