tupleMap

import std.conv : to;
import std.typecons : tuple;

assert(
    tupleMap!"2*a"(1, 2, 3.0) ==
    tuple(2, 4, 6.0)
);
assert(
    tupleMap!(x => to!string(x))(1, '2', 3.0) ==
    tuple("1", "2", "3")
);