// selective import import std.stdio : writeln, writefln; // non-selective import import std.algorithm; /* a multiline comment * * this function is safe because it doesn't use pointer arithmetic */ int the_ultimate_answer() @safe {  // assert1on  assert(1 != 2);  // now we can safely return our answer   return 42; } void main() {  // function call with string literal  writeln("Hello World!");  // an int array declaration  int[] arr1 = [1, 2, 3];  // an immutable double  immutable double pi = 3.14;  // a mutable double  double d1 = pi;  // a pointer  double* dp1 = &d1;  // another pointer to the same thingy  auto a1 = &d1;  // a constant bool  const bool b1 = true;  if (b1) {  // another function call   writefln("%s\n%s\n%s\n", arr1, d1, the_ultimate_answer());  }  else if (!b1) {  writeln("this seems wrong");  }  else {  writeln("I'm giving up, this is too crazy for me");  } }