Isn't it time there was a standard align statement?

It'd be really pleasant (in my opinion) if the next revision of the
C language actually allowed some portable control over data
alignment.

Compiler-specific mechanisms for this stuff are so varied that
it becomes impossible to even abstract the details away behind
preprocessor macros.

What I'd like to see:

/* per structure alignment */
align(16) struct xyz {
char x;
char y;
int z;
};

/* per member alignment (obviously padding before the first
member is illegal, so the entire structure would become aligned
in this case */
align(16) struct xyz {
align(16) char x;
char y;
int z;
};

/* per variable alignment */
align(16) unsigned int x;

I don't care about the syntax.

Now, obviously, C is meant to be implemented on everything from
self-aware weather-control mainframes, to motorized tie racks,
so in the case of the host implementation not supporting the specified
alignment, a warning should be emitted and either the closest or
natural alignment should be given. Warnings can obviously be made
fatal with compiler specific switches - and that's no business of the
language.

It just seems that this really should be standardized as it clearly
is useful for a vast number of programmers who need to get close to the
hardware but don't want to stray into assembly code (think Altivec,
SSE).
Sounds like EXACTLY the point of the C language, doesn't it?

I wouldn't mind so much if compiler implementors had come up with a
vaguely portable way of doing this, but they haven't even come close.
GCC and Intel have won joint first prize for 'most pleasant
implementation'
though (__attribute__ or _declspec()).

cheers,
MC

.

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