[Bug c++/65174] noexcept() returns true when operator delete with the object that has a throwing destructor

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65174

Jonathan Wakely  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2018-10-17
 CC||jason at gcc dot gnu.org
 Ever confirmed|0   |1

--- Comment #3 from Jonathan Wakely  ---
(In reply to Jonathan Wakely from comment #1)
> Hmm, interesting. When the operand of the delete expression is null the
> destructor is not invoked, so it can't throw.

That's C++11 [expr.delete] p6

  If the value of the operand of the delete-expression is not a null pointer
  value, the delete-expression will invoke the destructor (if any) for the
  object or the elements of the array being deleted.

> It's not obvious to me whether
> GCC's result is allowed by the standard or not.

The question is whether GCC is correct to determine that the unevaluated
operand of the noexcept operator will not invoke a destructor. Although it's
true that it won't throw, deciding that seems to involve some evaluation of the
unevaluated operand.

[Bug c++/65174] noexcept() returns true when operator delete with the object that has a throwing destructor

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65174

--- Comment #1 from Jonathan Wakely redi at gcc dot gnu.org ---
Hmm, interesting. When the operand of the delete expression is null the
destructor is not invoked, so it can't throw. It's not obvious to me whether
GCC's result is allowed by the standard or not.

[Bug c++/65174] noexcept() returns true when operator delete with the object that has a throwing destructor

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65174

--- Comment #2 from Jonathan Wakely redi at gcc dot gnu.org ---
FWIW clang and EDG both fail the first two static assertions here, while GCC
passes all three:

struct foo {
~foo() throw(int) {}
};

int main() {
static_assert( noexcept(delete static_castfoo*(nullptr)), );
static_assert( noexcept(delete static_castfoo*(0)), );
static_assert( !noexcept(delete (1+static_castfoo*(0))), );
}