https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115580
Bug ID: 115580
Summary: decltype of nullptr error with -Werror=nonnull
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: marcpawl at gmail dot com
Target Milestone: ---
-Werror=nonnull returns error when using nullptr to get type of member
function.
Even though we are using -Werror=nonnull, there should be no diagnostic
since the function is never evaluated, and it is non-virtual.
https://godbolt.org/z/3oh1199Wh
https://stackoverflow.com/questions/5580253/how-do-i-get-the-return-type-of-a-member-function-without-an-object
class WithMember {
public:
int foo();
};
decltype(((WithMember*)nullptr)->foo()) footype;
<source>:7:37: error: 'this' pointer is null [-Werror=nonnull]
7 | decltype(((WithMember*)nullptr)->foo()) footype;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
<source>:4:7: note: in a call to non-static member function 'int
WithMember::foo()'
4 | int foo();
| ^~~
<source>:7:37: error: 'this' pointer is null [-Werror=nonnull]
7 | decltype(((WithMember*)nullptr)->foo()) footype;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
<source>:4:7: note: in a call to non-static member function 'int
WithMember::foo()'
4 | int foo();
| ^~~
cc1plus: some warnings being treated as errors
Compiler returned: 1
