Re: Is it possible to filter variadics?

[Jakob Ovrum via Digitalmars-d-learn]

On Tuesday, 3 November 2015 at 23:41:10 UTC, maik klein wrote:
Is it possible to filter variadics for example if I would call
void printSumIntFloats(Ts...)(Ts ts){...}

printSumIntFloats(1,1.0f,2,2.0f);

I want to print the sum of all integers and the sum of all 
floats.


//Pseudo code
void printSumIntFloats(Ts...)(Ts ts){
    auto sumOfInts = ts
                      .filter!(isInteger)
                      .reduce(a => a + b);
    writeln(sumOfInts);
    ...
}

Is something like this possible?

import std.algorithm.iteration : sum;
import std.meta : allSatisfy, Filter;
import std.traits;
import std.typecons : tuple;
import std.range : only;

// These two are necessary since the ones in std.traits
// don't accept non-types
enum isIntegral(alias i) = std.traits.isIntegral!(typeof(i));
enum isFloatingPoint(alias f) = 
std.traits.isFloatingPoint!(typeof(f));

auto separateSum(T...)(T args)
        if(allSatisfy!(isNumeric, T))
{
	return tuple(only(Filter!(isIntegral, args)).sum(), 
only(Filter!(isFloatingPoint, args)).sum());
}

pure nothrow @safe unittest
{
        assert(separateSum(2, 2.0) == tuple(2, 2.0));
        assert(separateSum(3, 2.0, 5, 1.0, 1.0) == tuple(8, 4.0));
}