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();