import std;
enum counter=cast(immutable(void)*)[0].ptr;//ct counter, ignore
auto getcount()=>(*(cast(int*)counter));
auto count()=>(*(cast(int*)counter))++;

struct foo{
    void opDispatch(string s)(){
        enum _=count();//increases getcount by 1 each time its compiled
        static assert(0);
    }
}
void bar(foo){}
void foobar(foo){}
unittest{
    foo().bar;
    foo().bar;
}
unittest{
    foo().bar;
    foo().foobar;
    getcount.writeln;//4
}

foo().bar is being parsed and compiled 3 times; my instincts say this could be very slow for "builder patterns" and you may want to keep that in mind for large code bases that are slow if opDispatch (maybe with complex contracts?) is the only way to write something