995 – compile-time function return element of Tuple / const array

compile-time function return element of Tuple
--------------------------------------------------------------------
import std.stdio;
template Tuple(A...) { alias A Tuple; }
template eval(A...) { alias A eval; }
alias Tuple!("a","b") foo;
char[] retsth(int i) { return foo[i]; }
//Error: Integer constant expression expected instead of cast(uint)i
void main()
{
	writefln(eval!(foo[0]));
	//this is working
	writefln(eval!(retsth(0)));
}
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compile-time function return element of const array
--------------------------------------------------------------------
import std.stdio;
template eval(A...) { alias A eval; }
const char[] foo[2] = ["a","b"];
char[] retsth(int i) { return foo[i]; }
void main()
{
	writefln(eval!(foo[0]));
	//this is working (see #975)
	writefln(eval!(retsth(0)));
	//but this makes dmd crash
}
--------------------------------------------------------------------

Is this related to the bug ?
--------------------------------------------------------------------
import std.stdio;
template eval(A...) { alias A eval; }
char[] retsth(int i) {
	const char[] foo[2] = ["a","b"];
	return foo[i];
}
//Error: cannot evaluate retsth(0) at compile time
//Error: expression eval!(retsth(0)) is void and has no value
void main()
{
	writefln(eval!(retsth(0)));
}
--------------------------------------------------------------------
PS: Ultimately I would like to be able to do:
writefln(eval!(std.string.stripl(" test"));
Maybe some more string operations could be compile-time ready ?
I am not sure whether this will work if this bug get's fixed,
so maybe this is a feature req ;)

Added to DStress as
http://dstress.kuehne.cn/run/t/tuple_16_A.d
http://dstress.kuehne.cn/run/t/tuple_16_B.d
http://dstress.kuehne.cn/run/t/tuple_16_C.d
http://dstress.kuehne.cn/run/t/tuple_16_D.d 

The first example is not a bug; tuples must be evaluatable at compile time, and i of retsth(i) is not known at compile time when object code is generated for it. The other two are bugs.

Fixed DMD 1.009