On Thursday, 4 February 2016 at 17:52:16 UTC, Marco Leise wrote:
https://issues.dlang.org/show_bug.cgi?id=15645
Is this a possible fixed implementation? :
@property
Tuple!(sliceSpecs!(from, to)) slice(size_t from, size_t
to)() @trusted const
if (from <= to && to <= Types.length)
{
auto sliceMixinGenerator()
{
string rv;
for(auto i=from; i<to; ++i)
{
import std.conv : to;
rv ~= "returnValue[" ~ (i-from).to!string ~
"]=field[" ~ i.to!string ~"];";
}
return rv;
}
alias ReturnType = typeof(return);
ReturnType returnValue;
mixin(sliceMixinGenerator());
return returnValue;
}
///
unittest
{
Tuple!(int, string, float, double) a;
a[1] = "abc";
a[2] = 4.5;
auto s = a.slice!(1, 3);
static assert(is(typeof(s) == Tuple!(string, float)));
assert(s[0] == "abc" && s[1] == 4.5);
Tuple!(int, int, long) b;
b[1] = 42;
b[2] = 101;
auto t = b.slice!(1, 3);
static assert(is(typeof(t) == Tuple!(int, long)));
assert(t[0] == 42 && t[1] == 101);
}
I'm unsure about:
1. Removing 'ref' from the return type
2. Adding 'const' to the function signature
3. Is the new implementation less efficient for correctly aligned
tuples?
