struct.md

Struct Memory Layout

struct type

type Point struct { x, y int }

Initialized with new

new(Point)
+-------------+
|     *       | *Point
+------\------+
        \
         +-----------+
         |  0  |  0  | Point
         +-----------+

Initialized as a struct literal

p := Point{10, 20}
  +-----------+
  |  0  |  0  | Point
  +-----------+

pp := &Point{10, 20}
  +--------+
  |    *   | *Point
  +-----\--+
         \
          +-----------+
          |  0  |  0  | Point
          +-----------+

Memory layout of a struct of structs

type Rect1 struct { Min, Max Point }
type Rect2 struct { Min, Max *Point }

r1 := Rect1{Point{10, 20}, Point{50,60}}
    +-------------------+
    | 10 | 20 | 50 | 60 | Rect1
    +-------------------+

r2 := Rect2{&Point{10, 20}, &Point{50, 60}}
    +-----------------+
    |   *    |    *   | Rect2
    +----\-----------\+
          \           \
           +---------+ +---------+
           | 10 | 20 | | 50 | 60 | Point
           +---------+ +---------+