• John S. Skogtvedt (14/14) Nov 15 2006 A kind of "static foreach" already works for tuples,
• Max Samuha (7/7) Nov 15 2006 On Wed, 15 Nov 2006 11:05:02 +0100, "John S. Skogtvedt"
• Reiner Pope (5/13) Nov 15 2006 The important difference between 'static if' and 'if' is that 'static
• Max Samuha (3/16) Nov 16 2006 Thanks for the explanation. I need to dig deeper into the specs.

"John S. Skogtvedt" <jss2k2 chello.no> writes:

A kind of "static foreach" already works for tuples,
why not other constants as well?

Example:

import std.typetuple;

void main() {
	alias TypeTuple!(void, void, void) TL;
	foreach (t; TL) {
		pragma(msg, "this prints three times");
	}

	const char[] s = "abc";

	foreach (c; s) {
		pragma(msg, "and maybe this should as well?");
	}
}

Max Samuha <maxter i.com.ua> writes:

On Wed, 15 Nov 2006 11:05:02 +0100, "John S. Skogtvedt"
<jss2k2 chello.no> wrote:

Why 'foreach' and not 'static foreach' is used for compile time
iteration unlike 'static if' for compile time condition evaluation? Or
is 'static' necessary in 'static if' at all? Can't the compiler
determine whether 'if' is static based on the compile time
evaluability of the expression?

Reiner Pope <reiner.pope REMOVE.THIS.gmail.com> writes:

Max Samuha wrote:
 On Wed, 15 Nov 2006 11:05:02 +0100, "John S. Skogtvedt"
 <jss2k2 chello.no> wrote:
 
 Why 'foreach' and not 'static foreach' is used for compile time
 iteration unlike 'static if' for compile time condition evaluation? Or
 is 'static' necessary in 'static if' at all? Can't the compiler
 determine whether 'if' is static based on the compile time
 evaluability of the expression?

The important difference between 'static if' and 'if' is that 'static 
if' doesn't create a new scope, whereas 'if' does. The compile-time vs 
runtime dichotomy is just a consequence of that; deferring handling of 
different scopes to runtime is just too complex.

Max Samuha <maxter i.com.ua> writes:

On Thu, 16 Nov 2006 09:50:35 +1100, Reiner Pope
<reiner.pope REMOVE.THIS.gmail.com> wrote:

Max Samuha wrote:
 On Wed, 15 Nov 2006 11:05:02 +0100, "John S. Skogtvedt"
 <jss2k2 chello.no> wrote:
 
 Why 'foreach' and not 'static foreach' is used for compile time
 iteration unlike 'static if' for compile time condition evaluation? Or
 is 'static' necessary in 'static if' at all? Can't the compiler
 determine whether 'if' is static based on the compile time
 evaluability of the expression?

The important difference between 'static if' and 'if' is that 'static 
if' doesn't create a new scope, whereas 'if' does. The compile-time vs 
runtime dichotomy is just a consequence of that; deferring handling of 
different scopes to runtime is just too complex.

Thanks for the explanation. I need to dig deeper into the specs.