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Re: [avr-gcc-list] C Preprocessor question
From: |
Dave Hylands |
Subject: |
Re: [avr-gcc-list] C Preprocessor question |
Date: |
Sun, 11 Sep 2005 08:11:04 -0700 |
Hi Richard,
> Another possibility to play with:
>
> #define mymacro (foo, somenumber) \
> struct {Fifo fifo; uint8_t buf[somenumber]} foo;\
> const uint8_t *foo##ptr = (uint8_t*)&foo;
const uint8_t *foo;
uint8_t const *foo;
both create a pointer to a constant uint8_t. You can modify foo (i.e.
foo++ is legal) but you can't modify what foo points at (i.e. *foo =
'x'; wouldn't work).
uint8_t * const foo = something;
creates a constant pointer. You can't modify the pointer itself, but
you're free to modify what the pointer points at. foo++ is illegal,
but *foo = 'x'; is legal.
You can combine the two to create a constant pointer to a constant object.
--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/