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  1. import std.stdio;
  2. import core.stdc.stdlib;
  3.  
  4. /* ALLOCATION AND DEALLOCATION MECHANISMS */
  5.  
  6. T o_new(T, U...)(U args) if (is(T == class))
  7. {
  8.     size_t sz  = __traits(classInstanceSize, T);
  9.     void[] mem = calloc(sz, byte.sizeof)[0 .. sz];
  10.  
  11.     if (mem.length < sz) return null;
  12.  
  13.     auto ret = cast(T) mem.ptr;
  14.     (cast(byte[]) mem)[0 .. sz] = typeid(T).init[];
  15.  
  16.     static if (is(typeof(ret.__ctor(args))))
  17.         ret.__ctor(args);
  18.     else
  19.     {
  20.         static assert(
  21.             args.length == 0 && !is(typeof(&T.__ctor)),
  22.             "No ctor with arguments " ~ U.stringof ~
  23.             " present for an object of type " ~ T.stringof
  24.         );
  25.     }
  26.  
  27.     return ret;
  28. }
  29.  
  30. void o_delete(T)(T val) if (is(T == class))
  31. {
  32.     static if (is(typeof(val.__dtor())))
  33.         val.__dtor();
  34.  
  35.     free(cast(void*) val);
  36. }
  37.  
  38.  
  39. class Foo
  40. {
  41.      this() { writeln("ctor"); }
  42.     ~this() { writeln("dtor"); }
  43. }
  44.  
  45. void main()
  46. {
  47.     /* mallocated */
  48.     Foo bar = o_new!Foo();
  49.     writeln("some program");
  50.     o_delete(bar);
  51. }
Success #stdin #stdout 0.01s 2120KB
comments (?)
stdin
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Standard input is empty
stdout
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ctor
some program
dtor
https://ideone.com/JBJBa
language:
D (dmd 2.085.0)
created:
14 years ago
visibility:
public

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