https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #10 from Jiang An ---
Broken down into two smaller examples:
https://godbolt.org/z/YhK7PqE6s
```
#include
#include
int main() {
struct B {
B() {}
virtual ~B() { std::puts("C++11"); }
};
struct C { B b; };
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #9 from Jonathan Wakely ---
If there's a bug here, it's the value category of the ternary expression, not a
problem with typeid. Whether there's a problem with the value category depends
on how the DR is interpreted to apply to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #8 from Jonathan Wakely ---
The change makes the value category clk_rvalueref but I don't know what that
means in C++98 mode:
op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 0));
+ if (op1_lvalue_kind == clk_class)
+
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #7 from Jiang An ---
(In reply to Jonathan Wakely from comment #5)
> Prior to DR 616 the expression (true ? WrapB().b : WrapD().d) was a prvalue
> of type B, created by copying the B (or slicing the D when the condition is
> false).
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #6 from Jonathan Wakely ---
(In reply to Jonathan Wakely from comment #5)
> In C++98 the const B& is an lvalue, and in C++11 the B&& is an xvalue which
> is a glvalue. Either way, it's correct to treat it as a glvalue of
>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #5 from Jonathan Wakely ---
Prior to DR 616 the expression (true ? WrapB().b : WrapD().d) was a prvalue of
type B, created by copying the B (or slicing the D when the condition is
false). As an rvalue, it wasn't evaluated. That's
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #4 from Jonathan Wakely ---
This changed with r9-595-g955da5e5443724:
CWG 616, 1213 - value category of subobject references.
* tree.c (lvalue_kind): A reference to a subobject of a prvalue is
an
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #3 from Jiang An ---
(In reply to Richard Biener from comment #2)
> So you say GCC 9+ are wrong with -std=c++98 but OK with -std=c++11 or newer
> (the default)?
Yes.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
Richard Biener changed:
What|Removed |Added
CC||jason at gcc dot gnu.org
--- Comment
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114388
--- Comment #1 from Jiang An ---
Moreover, perhaps we should list N3055 in the implementation status page
(https://gcc.gnu.org/projects/cxx-status.html) since it did contain behavioral
change of typeid.
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