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();