Code style for property

[Andrey via Digitalmars-d-learn]

Hello, how better to declare properties, for example I have class:
> class Foo {
>     this(in int x, in int y, Bar bar) {
>         this.x = x;
>         this.y = y;
>         this.bar = bar;
>     }
> private:
>     int x;
>     int y;
>     Bar bar;
> }
And I want make access to read x, y and bar. Probably I should 
add prefix for private members, that is a question: what prefix 
should I use? Now I use prefix p_ (from the word property), but 
maybe prefix m_ is better and you need to use it for all private 
members?
Another question: what style is better for declare getters?
this:
> class Foo {
>     @property int x() { return p_x; // or m_x; }
>     @property int y() { return p_y; // or m_y; }
>     @property int bar() { return p_bar; // or m_bar; }
> }

or this:
> class Foo {
>     @property {
>         int x() { return p_x; }
>         int y() { return p_y; }
>         int bar() { return p_bar; }
>     }
> }

And one more question: should I add ref for property, to be able 
do this (if setter is declared):
> foo.x += 5