• Jonathan (5/5) Apr 06 2015 What's the best way to do this? I'm assuming this should be best
• Andrej Mitrovic via Digitalmars-d-learn (5/10) Apr 06 2015 I'm not even sure when or why this trait was introduced, but you could
• Jonathan (3/4) Apr 06 2015 Are static ifs always checked outside of runtime? Is it possible
• w0rp (4/8) Apr 07 2015 'static if' is always run at compile time, so it needs access to
• ketmar (8/14) Apr 06 2015 struct S {}

"Jonathan" <jadit2 gmail.com> writes:

What's the best way to do this? I'm assuming this should be best 
practice:
http://dlang.org/traits.html#isSame

struct S { }
writeln(__traits(isSame, S, S));

Andrej Mitrovic via Digitalmars-d-learn writes:

On 4/6/15, Jonathan via Digitalmars-d-learn
<digitalmars-d-learn puremagic.com> wrote:
 What's the best way to do this? I'm assuming this should be best
 practice:
 http://dlang.org/traits.html#isSame

 struct S { }
 writeln(__traits(isSame, S, S));

I'm not even sure when or why this trait was introduced, but you could
use a simple is() expression for this, e.g.:

static if (is(T == S)) { ... }

"Jonathan" <jadit2 gmail.com> writes:

 static if (is(T == V))


Are static ifs always checked outside of runtime? Is it possible 
for a static if condition to be undeterminable outside of 
runtime, or would such a condition throw a compiler error?

"w0rp" <devw0rp gmail.com> writes:

On Tuesday, 7 April 2015 at 06:37:50 UTC, Jonathan wrote:
 static if (is(T == V))


 Are static ifs always checked outside of runtime? Is it 
 possible for a static if condition to be undeterminable outside 
 of runtime, or would such a condition throw a compiler error?

'static if' is always run at compile time, so it needs access to 
compile time information. Fortunately, you can access quite a lot 
at compile time in D.

ketmar <ketmar ketmar.no-ip.org> writes:

On Mon, 06 Apr 2015 19:16:33 +0000, Jonathan wrote:

 What's the best way to do this? I'm assuming this should be best
 practice:
 http://dlang.org/traits.html#isSame
=20
 struct S { }
 writeln(__traits(isSame, S, S));


struct S {}

auto s0 =3D S();
auto s1 =3D S();

static if (is(typeof(s0) =3D=3D typeof(s1))) {
  pragma(msg, "Woe to the Republic.");
}
=