CHANGES BASED ON FURTHER COMMENTS
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x ^^ y is right associative, and has a precedence intermediate between
unary and postfix operators.
The type of x ^^ y is the same as the type of x * y.
* If either x or y are floating-point, the result is pow(x, y).
If both x and y are integers, the following rules apply:
* If x is the compile-time constant 0, x^^y is rewritten as (y==0)? 1 : 0
* If x is the compile-time constant 1, x^^y is rewritten as (y,1)
* If x is the compile-time constant -1 and y is an integer, x^^y is
rewritten as (y & 1) ? -1 : 1.
* If y == 0, x ^^ y is 1.
* If y > 0, x ^^ y is functionally equivalent to
{ auto u = x; foreach(i; 1..y) { u *= x; } return u; }
* If y < 0, an integer divide error occurs, regardless of the value of x.
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Note that by definining the 0,1, -1 cases as "rewriting" rules rather
than return values, it should be clearer that they don't apply to
variables having those values.
I think this covers everything useful, while avoiding nasty surprises
like
double y = x ^^ -1; // looks like reciprocal, but isn't!
// Yes, this IS the same problem you get with double y = 1/x.
// But that's doesn't make it acceptable. I have a possible solution to
that one, too.
I don't think we can afford to spend much more time on this.
Is everyone happy now?
