import std;

​

void myfun(int n){

    writeln(n);

}

​

​

void test(void delegate(int) fun) {

    fun(42);

}

​

void main() {

    test(toDelegate(&myfun)); // &myfun is a void function(int) so we need to convert it to delegate

    test((int value) { myfun(value); }); // or you can wrap it in delegate and pass value

    test(value => myfun(value)); // same as above, but using lambda syntax

}