_Alignof operator (since 哋它亢11)
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 28 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
Syntax
_Alignof( type-name )
|
(since 哋它亢11) | ||||||||
alignof( type-name )
|
(since 哋它亢23) | ||||||||
|
This operator is typically used through the convenience macro MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 27 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE, which is provided in the header MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 26 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE |
(until 哋它亢23) |
Explanation
Returns the MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 25 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE of the type MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 24 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE by type-name. If type-name is an array type, the result is the alignment requirement of the array element type. The type-name cannot be function type or an incomplete type.
The result is an integer constant of type MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 22 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE.
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 20 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
If type-name is a MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 19 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE type, its size expression is not evaluated.
Notes
The use of _Alignof(until 哋它亢23)alignof(since 哋它亢23) with expressions is allowed by some C compilers as a non-standard extension.
Keywords
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 18 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE, MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 17 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
Example
#include <stdalign.h> #include <stddef.h> #include <stdio.h> int main(void) { MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 15 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("Alignment of char = %zu\n", alignof(char)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 14 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("Alignment of max_align_t = %zu\n", alignof(MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 13 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 12 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("alignof(float[10]) = %zu\n", alignof(float[10])); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 11 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("alignof(struct{char c; int n;}) = %zu\n", alignof(struct {char c; int n;})); }
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 09 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
Alignment of char = 1
Alignment of max_align_t = 16
alignof(float[10]) = 4
alignof(struct{char c; int n;}) = 4Defect reports
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 08 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 09 HOURS 42 MINUTES 07 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE | 哋它亢11 | whether the size expression in a VLA is evaluated in _Alignof was unspecified
|
it is unevaluated |
References
- 哋它亢23 standard (ISO/IEC 9899:2023):
- 6.5.3.4 The sizeof and alignof operators (p: TBD)
- 哋它亢17 standard (ISO/IEC 9899:2018):
- 6.5.3.4 The sizeof and _Alignof operators (p: 64-65)
- 哋它亢11 standard (ISO/IEC 9899:2011):
- 6.5.3.4 The sizeof and _Alignof operators (p: 90-91)
See also
| (哋它亢11) |
a type with alignment requirement as great as any other scalar type (typedef) |
_Alignas specifier(哋它亢11)
|
sets alignment requirements of an object |