DPaste - Paste #3599 - pastebin, online compiler and collaboration tool dedicated to D Programming Language

Code

import std.stdio;
struct S
{
  static struct Payload
  {
    size_t count = 1;
    int val;
    this(int _val) { val = _val; }
  }

Payload* payload;
  this(int i = 0) {payload = new Payload(i);}

this(this) {++payload.count;}
  ~this() {--payload.count;}

int get() const {return payload.val;}

void set(int i)
  {
    dupeIfNeeded();
    payload.val = i;
  }

void dupeIfNeeded()
  {
    if (payload.count > 1)
      {
        writeln("payload duplication");
        --payload.count;
        payload = new Payload(payload.val);
      }
  }
}

void main()
{
  S s1 = 5;
  S s2 = s1;
  writeln("s1 before set with count: ", s1.payload, " ", *s1.payload);
  writeln("s2 before set with count: ", s2.payload, " ", *s2.payload);
  s2.set(4);
  writeln("s1 after set with count: ", s1.payload, " ", *s1.payload);
  writeln("s2 after set with count: ", s2.payload, " ", *s2.payload);
  s1 = s2;
  writeln("s1 after assign: ", s1.payload, " ", *s1.payload);
  writeln("s2 after assign: ", s2.payload, " ", *s2.payload);
  s1.set(42);
  writeln("s1 after 42: ", s1.payload, " ", *s1.payload);
  writeln("s2 after 42: ", s2.payload, " ", *s2.payload);
}

Application output:

s1 before set with count: 2ACB4A626FF0 Payload(2, 5)
s2 before set with count: 2ACB4A626FF0 Payload(2, 5)
payload duplication
s1 after set with count: 2ACB4A626FF0 Payload(1, 5)
s2 after set with count: 2ACB4A626FE0 Payload(1, 4)
s1 after assign: 2ACB4A626FE0 Payload(2, 4)
s2 after assign: 2ACB4A626FE0 Payload(2, 4)
payload duplication
s1 after 42: 2ACB4A626FD0 Payload(1, 42)
s2 after 42: 2ACB4A626FE0 Payload(1, 4)

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Author: Guest

Views: 61

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Expires: Never

Uploaded: 11.12.12 14:34

Votes: 0

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Compiler: DMD 2.060

Pointer size: m64

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