This piece of code creates a fizzbuzz string with template
parameters.
auto fizzbuzz(uint N)() {
string accumulate;
return fizzbuzz!N(accumulate);
}
auto fizzbuzz(uint N)(ref string result) if (N % 3 && N % 5) {
import std.conv : to;
result ~= N.to!string ~ "\n";
return fizzbuzz!(N - 1)(result);
}
auto fizzbuzz(uint N)(ref string result) if (!(N % 15)) {
result ~= "FizzBuzz\n";
return fizzbuzz!(N - 1)(result);
}
auto fizzbuzz(uint N)(ref string result) if (!(N % 3) && N % 5) {
result ~= "Fizz\n";
return fizzbuzz!(N - 1)(result);
}
auto fizzbuzz(uint N)(ref string result) if (!(N % 5) && N % 3) {
result ~= "Buzz\n";
return fizzbuzz!(N - 1)(result);
}
auto fizzbuzz(uint N : 0)(ref string result) {
return result;
}
void main() {
import std.stdio : writeln;
fizzbuzz!50().writeln();
}
https://godbolt.org/z/hWENgc
In the generated assembly, it looks like it is creating a lot of
runtime instructions, contrary to my belief that templated codes
are purely compile-time. I was expecting that the compiler would
deduce the fizzbuzz string until 50 in compile-time and just
print it in the run-time. Why is this not the case?
