• hunt (7/7) Aug 01 2013 Hello, guys. It is weird to ask about my homework here, but I
• Timon Gehr (4/11) Aug 01 2013 This should get you started:
• John Colvin (4/23) Aug 01 2013 Also, say hello to the most esoteric expression I can think of:
• monarch_dodra (23/48) Aug 02 2013 http://dpaste.dzfl.pl/f3d7c828

"hunt" <jaeyoep gmail.com> writes:

Hello, guys. It is weird to ask about my homework here, but I 
haven't gotten a proper answer yet. It's about D feature...maybe..

http://dpaste.dzfl.pl/905d6ad7

Question is that "Investigate how D allows you to defend your 
definition of Map so that it may be used only with a type of key 
that is comparable, and place this defense in your solution."

Please leave your comments here. Thank you so much.

Timon Gehr <timon.gehr gmx.ch> writes:

On 08/02/2013 01:34 AM, hunt wrote:
 Hello, guys. It is weird to ask about my homework here, but I haven't
 gotten a proper answer yet. It's about D feature...maybe..

 http://dpaste.dzfl.pl/905d6ad7

 Question is that "Investigate how D allows you to defend your definition
 of Map so that it may be used only with a type of key that is
 comparable, and place this defense in your solution."

 Please leave your comments here. Thank you so much.

This should get you started:

http://dlang.org/concepts.html
http://dlang.org/traits.html#compiles

"John Colvin" <john.loughran.colvin gmail.com> writes:

On Thursday, 1 August 2013 at 23:48:33 UTC, Timon Gehr wrote:
 On 08/02/2013 01:34 AM, hunt wrote:
 Hello, guys. It is weird to ask about my homework here, but I 
 haven't
 gotten a proper answer yet. It's about D feature...maybe..

 http://dpaste.dzfl.pl/905d6ad7

 Question is that "Investigate how D allows you to defend your 
 definition
 of Map so that it may be used only with a type of key that is
 comparable, and place this defense in your solution."

 Please leave your comments here. Thank you so much.

 This should get you started:

 http://dlang.org/concepts.html
 http://dlang.org/traits.html#compiles

Also, say hello to the most esoteric expression I can think of: 
D's "is" expression

http://dlang.org/expression.html#IsExpression

"monarch_dodra" <monarchdodra gmail.com> writes:

On Thursday, 1 August 2013 at 23:57:47 UTC, John Colvin wrote:
 On Thursday, 1 August 2013 at 23:48:33 UTC, Timon Gehr wrote:
 On 08/02/2013 01:34 AM, hunt wrote:
 Hello, guys. It is weird to ask about my homework here, but I 
 haven't
 gotten a proper answer yet. It's about D feature...maybe..

 http://dpaste.dzfl.pl/905d6ad7

 Question is that "Investigate how D allows you to defend your 
 definition
 of Map so that it may be used only with a type of key that is
 comparable, and place this defense in your solution."

 Please leave your comments here. Thank you so much.

 This should get you started:

 http://dlang.org/concepts.html
 http://dlang.org/traits.html#compiles

 Also, say hello to the most esoteric expression I can think of: 
 D's "is" expression

 http://dlang.org/expression.html#IsExpression

http://dpaste.dzfl.pl/f3d7c828

//Via constraits
//This will do a template mismatch
struct Map1(T)
if (is(typeof(T.init < T.init)))
{
     //Who cares	
}

//Via (explicit) compilation errors
struct Map2(T)
{
     static assert (is(typeof(T.init < T.init)), "Error, " ~ T ~ " 
is not comparable.");
}

void main()
{
     struct S {} //Not comparable
     assert( is(Map1!int));
     assert(!is(Map1!S));
     assert( is(Map2!int));
     assert(!is(Map2!S));
}