• FoxyBrown (3/3) Jul 09 2017 How can we iterate over a variadic and have it's index. I'll do
• drug (9/13) Jul 09 2017 auto foo(Types...)()
• Lamex (31/34) Jul 09 2017 import std.stdio;
• H. S. Teoh via Digitalmars-d-learn (16/19) Jul 10 2017 Easy:
• ag0aep6g (3/10) Jul 10 2017 even

FoxyBrown <Foxy Brown.IPT> writes:

How can we iterate over a variadic and have it's index. I'll do 
different things depend on if it's an even or odd index, but 
seems to be no way to get it.

drug <drug2004 bk.ru> writes:

10.07.2017 01:21, FoxyBrown пишет:
 How can we iterate over a variadic and have it's index. I'll do 
 different things depend on if it's an even or odd index, but seems to be 
 no way to get it.
 

auto foo(Types...)()
{
	foreach(T; Types)
	{
		// do what you need
	}
}
index could be added like usual

Lamex <Lamex dfghjkl.iuyt> writes:

On Sunday, 9 July 2017 at 22:21:59 UTC, FoxyBrown wrote:
 How can we iterate over a variadic and have it's index. I'll do 
 different things depend on if it's an even or odd index, but 
 seems to be no way to get it.


import std.stdio;
import std.typecons, std.meta;

template indexedAllSatisfy(alias F, T...)
{
     bool doTest()
     {
         bool result = true;
         import std.range: iota;
         foreach(i; aliasSeqOf!(iota(0, T.length)))
             result &= F!(T[i], i, T.length);
         return result;
     }
     enum indexedAllSatisfy = doTest();
}

unittest
{
     template evenIntString(T, int index, int length)
     {
         static if (length & 1)
             enum evenIntString = false;
         else static if (index & 1)
             enum evenIntString = is(T == string);
         else
             enum evenIntString = is(T == int);
     }

     static assert(indexedAllSatisfy!(evenIntString, int, string, 
int, string));
     static assert(!indexedAllSatisfy!(evenIntString, int , 
string, char, Object));
}

"H. S. Teoh via Digitalmars-d-learn" <digitalmars-d-learn puremagic.com> writes:

On Sun, Jul 09, 2017 at 10:21:59PM +0000, FoxyBrown via Digitalmars-d-learn
wrote:
 How can we iterate over a variadic and have it's index. I'll do
 different things depend on if it's an even or odd index, but seems to
 be no way to get it.

Easy:

	auto func(Args...)(Args args) {
		foreach (i, arg; args) {
			if (i % 2) {
				// even
				... // do something with arg
			} else {
				// odd
				... // do something with arg
			}
		}
	}


T

-- 
"Real programmers can write assembly code in any language. :-)" -- Larry Wall

ag0aep6g <anonymous example.com> writes:

On 07/10/2017 08:31 PM, H. S. Teoh via Digitalmars-d-learn wrote:
 			if (i % 2) {
 				// even

odd

 				... // do something with arg
 			} else {
 				// odd

even

 				... // do something with arg
 			}