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();