On 03/10/2018 09:48 PM, Nordlöw wrote:
If I have a function
bool f(Rs...)(Rs rs)
is it somehow possible to map and forward all its arguments `rs` to
another function
bool g(Rs...)(Rs rs);
through a call to some map-and-forward-like-function `forwardMap` in
something like
bool f(Rs...)(Rs rs)
{
alias someArbitraryFun = _ => _;
return g(forwardMap!(someArbitraryFun)(rs));
}
?
Not with that syntax, as far as I know. A function can't return an alias
seq like that.
But it can return a std.typecons.Tuple. You'd have to add `.expand` then:
return g(forwardMap!someArbitraryFun(rs).expand);
What should the definition of forwardMap look like?
Not tested beyond `f(1, 2.3, "foo")`:
----
auto forwardMap(alias fun, Ts ...)(Ts things)
{
import std.meta: aliasSeqOf, staticMap;
import std.range: iota;
import std.typecons: Tuple;
alias NewType(size_t i) = typeof(fun(things[i]));
alias NewTypes = staticMap!(NewType,
aliasSeqOf!(iota(things.length)));
Tuple!NewTypes results;
static foreach (i, thing; things) results[i] = fun(thing);
return results;
}
----
I wouldn't call it "forwardMap". "tupleMap" or "seqMap" maybe?
Does Phobos contain something like this already?
Not that I know of.
