Here's a little experiment I was trying out earlier today in order to try and
convert foreach-style code to using UFCS of ranges:
//////////////////////////////////////////////
import std.algorithm, std.range, std.stdio;
void main()
{
size_t s = 0;
void essify(size_t n)
{
writeln("n = ", n);
++s;
}
auto filteredRange = iota(0, 10).filter!(a => (a % 2));
filteredRange.map!(a => essify(a));
writeln(s);
foreach (n; filteredRange)
{
essify(n);
}
writeln(s);
}
//////////////////////////////////////////////
I'd assumed the two uses of filteredRange would produce equivalent results, but
in fact the transformation using map does nothing -- the writeln statement
inside the essify() function never gets triggered, suggesting the function body
is never executed.
Can anyone advise why, and whether there's a nice range iteration option to
ensure that this function gets called using each element of the filteredRange?
