• Bahman Movaqar (18/18) Jul 11 2016 What should be signature of `foo` in the following piece of code?
• Mike Parker (2/10) Jul 11 2016 auto foo(R)(R r) { ... }
• Bahman Movaqar (6/7) Jul 12 2016 That did it. Thanks.
• Mike Parker (4/10) Jul 12 2016 It's just a function template. It's what you use whenever you
• H. S. Teoh via Digitalmars-d-learn (9/23) Jul 12 2016 Better yet:

Bahman Movaqar <Bahma BahmanM.com> writes:

What should be signature of `foo` in the following piece of code?

    auto foo(range r) {
      // do something with the `r`
    }

    void main() {
      foo([1,2,3].map!(x => x*x));
    }


Right now I use `.array` to convert the range before passing:

    auto foo(int[] r) {
      // do something with the `r`
    }

    void main() {
      foo([1,2,3].map!(x => x*x).array);
    }

But it doesn't feel right.

Thanks,
-- 
Bahman

Mike Parker <aldacron gmail.com> writes:

On Tuesday, 12 July 2016 at 03:57:09 UTC, Bahman Movaqar wrote:
 What should be signature of `foo` in the following piece of 
 code?

     auto foo(range r) {
       // do something with the `r`
     }

     void main() {
       foo([1,2,3].map!(x => x*x));
     }

auto foo(R)(R r) { ... }

Bahman Movaqar <Bahma BahmanM.com> writes:

On 07/12/2016 11:07 AM, Mike Parker wrote:
 auto foo(R)(R r) { ... }

That did it.  Thanks.
Out of curiosity, does the same pattern apply to functions which take
`tuple`s as input arguments?

-- 
Bahman

Mike Parker <aldacron gmail.com> writes:

On Tuesday, 12 July 2016 at 07:50:34 UTC, Bahman Movaqar wrote:
 On 07/12/2016 11:07 AM, Mike Parker wrote:
 auto foo(R)(R r) { ... }

 That did it.  Thanks.
 Out of curiosity, does the same pattern apply to functions 
 which take
 `tuple`s as input arguments?

It's just a function template. It's what you use whenever you 
need to deal with generic types.

https://dlang.org/spec/template.html

"H. S. Teoh via Digitalmars-d-learn" <digitalmars-d-learn puremagic.com> writes:

On Tue, Jul 12, 2016 at 06:37:35AM +0000, Mike Parker via Digitalmars-d-learn
wrote:
 On Tuesday, 12 July 2016 at 03:57:09 UTC, Bahman Movaqar wrote:
 What should be signature of `foo` in the following piece of code?
 
     auto foo(range r) {
       // do something with the `r`
     }
 
     void main() {
       foo([1,2,3].map!(x => x*x));
     }
 
 

 
 auto foo(R)(R r) { ... }

Better yet:

	import std.range.primitives;
	auto foo(R)(R r) if (isInputRange!R) { ... }

This is to ensure R is actually a range, so that, for example, foo(123)
will be rejected at compile-time.


T

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