Make "`aa[key]`" use the same runtime call as "`key in aa`". The runtime calls these were using were different, but with equivalent definitions. With `ldc -O3`, the following functions now all compile to the exact same code: {{{ int[int] y; void foo(int x) { if (x in y) { auto z = x in y; sink(*z); } } void bar(int x) { if (x in y) { sink(y[x]); } } void baz(int x) { if (auto p = x in y) { sink(*p); } } }}}

interface Inter
{
    int func();
}

extern(C) int printf(char*, ...);

class InterClass : Inter
{
    int func()
    {
        return printf("InterClass.func()\n");
    }
}

alias int delegate() dg_t;

void main()
{
    scope c = new InterClass;

    {
    Inter i = cast(Inter)c;
        {
        dg_t dg = &i.func;
            {
            int j = dg();
            }
        }
    }
}