Standard library header (C++11)(until C++20), <stdalign.h> (C++11) (original) (raw)
This header was originally in the C standard library as <stdalign.h>.
C compatibility header. alignas and alignof are keywords in C++, but they were not keywords in C until C23.
| Macros | |
|---|---|
| __alignas_is_defined(C++11)(deprecated) | C compatibility macro constant, expands to integer literal 1 (macro constant) [edit] |
| __alignof_is_defined(C++11)(deprecated) | C compatibility macro constant, expands to integer literal 1 (macro constant) [edit] |
[edit] Notes
<cstdalign> is deprecated in C++17 and removed in C++20. Corresponding <stdalign.h> is still available in C++20.
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3827 | C++11 | C programs no longer need the compatibilitymacro __alignas_is_defined since C23 | deprecated thismacro in C++ |