On Tuesday, 21 April 2015 at 19:17:56 UTC, kevin wrote:
On Tuesday, 21 April 2015 at 19:13:34 UTC, Meta wrote:
On Tuesday, 21 April 2015 at 19:11:43 UTC, John Colvin wrote:
On Tuesday, 21 April 2015 at 19:06:39 UTC, kevin wrote:
enum bool isInputRange = is(typeof(
(inout int = 0)
{
R r = R.init; // can define a range object
if (r.empty) {} // can test for empty
r.popFront(); // can invoke popFront()
auto h = r.front; // can get the front of the range
}));
[...]
Don't lambdas need a => token?
No, D has two variants of function/delegate literal or lambda
syntax:
1) with "=>": parameters => expression
Some examples:
(int a) => a + 2
a => a + 2
(a, b) => a + b
() => 2
2) with braces: (parameters) {statements}
Same examples as above:
(int a) {return a + 2;}
(a) {return a + 2;}
(a, b) {return a + b;}
{return 2;}
As you can see, a lot is optional there.
In the spec: http://dlang.org/expression.html#FunctionLiteral
Also, what is the purpose of typeof? I would have expected a
simple is() to work just fine.
(In this most simple form,) `is` evaluates to true if the
argument is a valid type. A function/delegate literal isn't a
type.
If you passed the lambda expression itself to `is`, the result
would always be false. As it is, the result is true when the
lambda expression compiles (so it has a valid type).
More about the IsExpression:
http://dlang.org/expression.html#IsExpression
