Foo* foo = new Foo(a,v);

Foo* foo = new(ptr,std::nothrow)Foo[];
Foo* foo = new(ptr)Foo();
Foo* foo = new(FOO(ptr) )Foo();

Foo* foo = new(ptr,std::nothrow)Foo[];
Foo* foo = new(ptr)Foo();
Foo* foo = new(FOO(ptr) )Foo();