https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108619
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |redi at gcc dot gnu.org
--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This fails for all modes from C++11 to C++20:
#include <memory>
#include <vector>
#include <type_traits>
class a {
~a() = default;
friend class b;
};
class b {
template<typename C>
struct alloc {
std::allocator<C> a;
alloc() { }
template<typename U> alloc(const alloc<U>&) { }
using value_type = C;
C* allocate(std::size_t n) { return a.allocate(n); }
void deallocate(C* p, std::size_t n) { return a.deallocate(p, n); }
template<typename U>
void destroy(U* p){
if constexpr (std::is_array_v<U>){
for(auto& elem : *p){
(destroy)(std::addressof(elem));
}
} else {
p->~U();
}
}
};
std::vector<a,alloc<a>> v;
public:
void f(){
v.emplace_back();
}
};
I have a patch ...
