This code fails to compile, but it shouldn't.

void foo1(Object[] a){}
void foo2()(Object[] a){}
void foo3(T)(T[] a){}

void bar1(Object[][] a){}
void bar2()(Object[][] a){}
void bar3(T)(T[][] a){}

void main()
{
    foo1([]);   // OK
    foo2([]);   // NG
    foo3([]);   // OK, T == void

    bar1([[]]); // OK
    bar2([[]]); // NG
    bar3([[]]); // OK, T == void
}