https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110312
Bug ID: 110312
Summary: -Wcast-align=strict warning despite alignas
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: f.heckenb...@fh-soft.de
Target Milestone: ---
% cat test.cpp
alignas (int) char a[sizeof (int)];
auto b = reinterpret_cast <int &> (a);
% g++ -c -Wcast-align=strict test.cpp
test.cpp:2:10: warning: cast from 'char (*)[4]' to 'int*' increases required
alignment of target type [-Wcast-align]
I'd kind of understand the warning if I was casting &a to int* because the
alignas information might get lost when taking the address. So I tried casting
a reference, but apparently (telling from the message), gcc implements this via
a pointer cast anyway, so it doesn't help.
FWIW, I got this when I tried to replace aligned_storage_t (which is deprecated
in C++23 for reasons I don't really understand TBH) with a std::byte array as
suggested. Does this mean that I simply can't use -Wcast-align=strict then?
