Michel Fortin wrote:
On 2010-02-17 12:07:05 -0500, Andrei Alexandrescu
<[email protected]> said:
Searching a value in a literal should actually be allowed:
x in [10, 20, 30, 0]
is great because the compiler has complete discretion in how to
conduct the search (e.g. linear vs. binary vs. hash search; it can
take the initiative of presorting the literal). But general search in
an unstructured range... maybe not.
Are you talking about literals or compile-time constants? A literal can
be built using variables and functions, such as:
x in [a, b, c, d, e]
This would be mostly equivalent to this:
x == a || x == b || x == c || x == d || x == e
I'd tend to allow it as it makes it easier to write and read
conditionals with repeated comparisons against the same variable.
I was thinking CTFE-able array literals, but I think linear search in a
short array (in a way all array literals are O(1)) is fair game too.
But I guess that's less important than supporting compile-time constants:
const allowedCharacters = ['0','1','2','3','4','5','6','7','8','9'];
if (x in allowedCharacters)
...;
Indeed.
Andrei
