• Gavin Maye (17/17) Feb 16 2016 Say you have
• rsw0x (4/21) Feb 16 2016 If I understand you correctly, you want pattern matching
• =?UTF-8?Q?Ali_=c3=87ehreli?= (22/39) Feb 16 2016 std.traits.TemplateArgsOf:
• Gavin Maye (2/23) Feb 16 2016 Thanks Ali!

Gavin Maye <immno here.com> writes:

Say you have

class Foo(type1,type2)
{
    ....
}

And a concrete Foo is passed as a parameter to another template, 
is there a way to get type1 and type2 from Foo so you can use 
them in the new template... For example..

class Bar(FooType)
{
     FooType.type1 DoSomething() { ... }
}

or Even something like

class Bar(FooType) : Baz!(FooType.type1)
{
     FooType.type1 DoSomething() { ... }
}

rsw0x <anonymous anonymous.com> writes:

On Tuesday, 16 February 2016 at 18:34:40 UTC, Gavin Maye wrote:
 Say you have

 class Foo(type1,type2)
 {
    ....
 }

 And a concrete Foo is passed as a parameter to another 
 template, is there a way to get type1 and type2 from Foo so you 
 can use them in the new template... For example..

 class Bar(FooType)
 {
     FooType.type1 DoSomething() { ... }
 }

 or Even something like

 class Bar(FooType) : Baz!(FooType.type1)
 {
     FooType.type1 DoSomething() { ... }
 }

If I understand you correctly, you want pattern matching

i.e,
http://dpaste.dzfl.pl/d8de0a004f59

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 02/16/2016 10:34 AM, Gavin Maye wrote:
 Say you have

 class Foo(type1,type2)
 {
     ....
 }

 And a concrete Foo is passed as a parameter to another template, is
 there a way to get type1 and type2 from Foo so you can use them in the
 new template... For example..

 class Bar(FooType)
 {
      FooType.type1 DoSomething() { ... }
 }

 or Even something like

 class Bar(FooType) : Baz!(FooType.type1)
 {
      FooType.type1 DoSomething() { ... }
 }

std.traits.TemplateArgsOf:

   http://dlang.org/phobos/std_traits.html#TemplateArgsOf

import std.traits;

class Foo(type1,type2)
{}

class Bar(FooType)
{
     // pragma(msg, TemplateArgsOf!FooType);

     alias ReturnType = TemplateArgsOf!FooType[0];

     ReturnType DoSomething() {
         return ReturnType.init;
     }
}

void main() {
     auto b = new Bar!(Foo!(string, double));
}

However, there are other ways of achieving the same thing at least when 
returning from a function, e.g.:

     auto DoSomething() {}

(Check out typeof(return) which may be useful in that case.)

Ali

Gavin Maye <immno here.com> writes:

On Tuesday, 16 February 2016 at 19:00:19 UTC, Ali Çehreli wrote:
 std.traits.TemplateArgsOf:

   http://dlang.org/phobos/std_traits.html#TemplateArgsOf

 import std.traits;

 class Foo(type1,type2)
 {}

 class Bar(FooType)
 {
     // pragma(msg, TemplateArgsOf!FooType);

     alias ReturnType = TemplateArgsOf!FooType[0];

     ReturnType DoSomething() {
         return ReturnType.init;
     }
 }

 void main() {
     auto b = new Bar!(Foo!(string, double));
 }

 However, there are other ways of achieving the same thing at 
 least when returning from a function, e.g.:

     auto DoSomething() {}

 (Check out typeof(return) which may be useful in that case.)

 Ali

Thanks Ali!