• pineapple (17/17) Jun 15 2016 Here's a simple code example to illustrate what I expected to
• Basile B. (3/20) Jun 15 2016 This syntax passes:
• Steven Schveighoffer (4/23) Jun 15 2016 This isn't valid syntax.
• Basile B. (17/40) Jun 15 2016 I didn't try to instanciate previously. It works a bit with a

pineapple <meapineapple gmail.com> writes:

Here's a simple code example to illustrate what I expected to 
work and didn't - is this a mistake in my syntax or a limitation 
of the language?

     template SomeTemplate(alias func){
         auto templatefunc(T)(int x){
             return func!T(x);
         }
     }

     // Valid
     auto somefunc(T)(int x){
         return cast(T) x;
     }
     alias fn1 = SomeTemplate!somefunc;

     // Not valid
     alias fn2 = SomeTemplate!(
         (T)(int x){return cast(T) x;}
     );

Basile B. <b2.temp gmx.com> writes:

On Wednesday, 15 June 2016 at 22:27:38 UTC, pineapple wrote:
 Here's a simple code example to illustrate what I expected to 
 work and didn't - is this a mistake in my syntax or a 
 limitation of the language?

     template SomeTemplate(alias func){
         auto templatefunc(T)(int x){
             return func!T(x);
         }
     }

     // Valid
     auto somefunc(T)(int x){
         return cast(T) x;
     }
     alias fn1 = SomeTemplate!somefunc;

     // Not valid
     alias fn2 = SomeTemplate!(
         (T)(int x){return cast(T) x;}
     );

This syntax passes:

     alias fn2(T) = SomeTemplate!((int x){return cast(T) x;});

Steven Schveighoffer <schveiguy yahoo.com> writes:

On 6/15/16 7:52 PM, Basile B. wrote:
 On Wednesday, 15 June 2016 at 22:27:38 UTC, pineapple wrote:
 Here's a simple code example to illustrate what I expected to work and
 didn't - is this a mistake in my syntax or a limitation of the language?

     template SomeTemplate(alias func){
         auto templatefunc(T)(int x){
             return func!T(x);
         }
     }

     // Valid
     auto somefunc(T)(int x){
         return cast(T) x;
     }
     alias fn1 = SomeTemplate!somefunc;

     // Not valid
     alias fn2 = SomeTemplate!(
         (T)(int x){return cast(T) x;}


This isn't valid syntax.

I don't think you can create anonymous templates. I could be wrong.

-Steve

Basile B. <b2.temp gmx.com> writes:

On Wednesday, 15 June 2016 at 23:52:56 UTC, Basile B. wrote:
 On Wednesday, 15 June 2016 at 22:27:38 UTC, pineapple wrote:
 Here's a simple code example to illustrate what I expected to 
 work and didn't - is this a mistake in my syntax or a 
 limitation of the language?

     template SomeTemplate(alias func){
         auto templatefunc(T)(int x){
             return func!T(x);
         }
     }

     // Valid
     auto somefunc(T)(int x){
         return cast(T) x;
     }
     alias fn1 = SomeTemplate!somefunc;

     // Not valid
     alias fn2 = SomeTemplate!(
         (T)(int x){return cast(T) x;}
     );

 This syntax passes:

     alias fn2(T) = SomeTemplate!((int x){return cast(T) x;});

I didn't try to instanciate previously. It works a bit with a 
lambda to the
extent that the alias has the template parameter list.

import std.stdio;

template A(alias func)
{
     auto a(T)(int x)
     {
         return func!T(x);
     }
}

alias spec(T) = A!(x => (cast(T) x));

void main(string[] args)
{
     writeln((spec!byte).a!int(257)); // 1
}