On 7/15/2014 4:52 PM, Steve Sobel wrote:
So in my opinion, and without prescribing the exact solution,
volatility is an important enough concept in embedded to merit a
standard solution that can be mechanically verified.
There is another way. The peek() and poke() functions are primitive. You can
wrap a "pointer to volatile" in its own type, and in that type, control access
to the pointer so it cannot be used outside of peek/poke.
For example, off the top of my head:
struct VolatilePointerToUint {
private:
size_t ptr;
public:
this(size_t ptr) { this.ptr = ptr; }
uint read() { return peek(cast(uint*)ptr); }
void write(uint value) { poke(cast(uint*)ptr, value); }
}
You'd probably wish to flesh this out a bit more, but it's the general idea.
It's a zero cost abstraction. D has very capable abilities to create types that
are restricted versions of other types - this should be explored and exhausted
before considering language extensions.
