https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89090
Bug ID: 89090
Summary: vector.tcc uses "if constexpr" in C++11 mode
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: csaba_22 at yahoo dot co.uk
Target Milestone: ---
vector.tcc contains the following at line 613
#if __cplusplus >= 201103L
template<typename _Tp, typename _Alloc>
void
vector<_Tp, _Alloc>::
_M_default_append(size_type __n)
{
if (__n != 0)
{
const size_type __size = size();
size_type __navail = size_type(this->_M_impl._M_end_of_storage
- this->_M_impl._M_finish);
if (__size > max_size() || __navail > max_size() - __size)
__builtin_unreachable();
if (__navail >= __n)
{
_GLIBCXX_ASAN_ANNOTATE_GROW(__n);
this->_M_impl._M_finish =
std::__uninitialized_default_n_a(this->_M_impl._M_finish,
__n, _M_get_Tp_allocator());
_GLIBCXX_ASAN_ANNOTATE_GREW(__n);
}
else
{
const size_type __len =
_M_check_len(__n, "vector::_M_default_append");
pointer __new_start(this->_M_allocate(__len));
#if __cplusplus >= 201103L
if constexpr (__use_relocate)
{
__try
{
std::__uninitialized_default_n_a(__new_start + __size,
__n, _M_get_Tp_allocator());
}
__catch(...)
{
_M_deallocate(__new_start, __len);
__throw_exception_again;
}
std::__relocate_a(this->_M_impl._M_start,
this->_M_impl._M_finish,
__new_start, _M_get_Tp_allocator());
}
else
#endif
{
pointer __destroy_from = pointer();
__try
{
std::__uninitialized_default_n_a(__new_start + __size,
__n, _M_get_Tp_allocator());
__destroy_from = __new_start + __size;
std::__uninitialized_move_if_noexcept_a(
this->_M_impl._M_start, this->_M_impl._M_finish,
__new_start, _M_get_Tp_allocator());
}
__catch(...)
{
if (__destroy_from)
std::_Destroy(__destroy_from, __destroy_from + __n,
_M_get_Tp_allocator());
_M_deallocate(__new_start, __len);
__throw_exception_again;
}
std::_Destroy(this->_M_impl._M_start,
this->_M_impl._M_finish,
_M_get_Tp_allocator());
}
_GLIBCXX_ASAN_ANNOTATE_REINIT;
_M_deallocate(this->_M_impl._M_start,
this->_M_impl._M_end_of_storage
- this->_M_impl._M_start);
this->_M_impl._M_start = __new_start;
this->_M_impl._M_finish = __new_start + __size + __n;
this->_M_impl._M_end_of_storage = __new_start + __len;
}
}
}
The two nested "#if __cplusplus >= 201103L" checks are suspicious (copy-paste
error?)
Generating preprocessor output from a one-liner of #include <vector> with
-std=c++11 -save-temps results in a .ii file which shouldn't even compile in
C++11 mode.
