@related: [[C]] [[Programming]] [[C++]] [[struct]]

typedef is usefull to decribe new types :

  typedef char* pchar;

  typedef struct {
   int lenght;
   char* ptr;
  } buffer_t;


But how to rewrite this without using typedef ?

  typedef int vint2[[2]];

  int fAllocTypedefPtr(vint2* & a  ) { //symbol is int (* &)[[2]]
  a = new int[[1]][[2]];
  a[[0]][[0]] = 2;  //ok
  }

  int f(int (*&a)[[2]]) { }  // for your curiousity

  <Adrinael> boost::multi_array stores it in a contiguous array.

===ARRAY COPY===

I suppose that typedef [[C]] keyword dont get along with arrays :

please explain me this :

  typedef float vfloat3[[3]];

  int main() {
  vfloat3 a= { 0, 1, 2 };
  cout << a[[0]] << a[[1]] << a[[2]] <<endl; // ok : 012
  vfloat3 b;
  // b=a; // error: ISO C++ forbids assignment of arrays //gcc complain
  return 0;
  }

Of course if you replace vfloat3 by float[[3]] , it does not make sense
but why allowing typedef with arrays if you can not fully use them ?

===ARRAY COPY CONSTRUCTOR NEEDED BY STL===

Doesnt work better with [[C++]] STL

  #include <vector>
  #include <iostream>
  using namespace std;

  typedef float vfloat3[[3]];

  int main()
  {

  vfloat3 a= { 0, 1, 2 };
  cout << a[[0]] << a[[1]] << a[[2]] <<endl; // ok : 012
  vector<vfloat3> v;
  cout<<v.size() <<endl; // ok : 0
  v.push_back(a); //gives errors on compilation (g++ and msvc)
  return 0;
  }

  /*

  /usr/include/c++/3.3.1/bits/stl_vector.h:603:
  instantiated from `void std::vector<_Tp, _Alloc>::push_back(const _Tp&)
  [[with _Tp = float[[3]], _Alloc = std::allocator<float[[3]]>]]'


  c:\program files\microsoft visual studio\vc98\include\xutility(39) :
  error C2440: '=' : cannot convert from 'const float [[3]]' to 'float [[3]]'
        There is no context in which this conversion is possible
  c:\program files\microsoft visual studio\vc98\include\vector(170) :
  see reference to function template instantiation
  'void __cdecl std::fill(float (*)[[3]],float (*)[[3]],const float (&)[[3]])' being compiled
  c:\program files\microsoft visual studio\vc98\include\xutility(25) :
  error C2106: '=' : left operand must be l-value
  c:\program files\microsoft visual studio\vc98\include\vector(174) :
  see reference to function template instantiation
  'float (*__cdecl std::copy_backward(float (*)[[3]],float (*)[[3]],float (*)[[3]]))[[3]]' being compiled
  c:\program files\microsoft visual studio\vc98\include\xmemory(34) :
  error C2538: new : cannot specify initializer for arrays
  c:\program files\microsoft visual studio\vc98\include\xmemory(66) :
  see reference to function template instantiation
  'void __cdecl std::_Construct(float (*)[[3]],const float (&)[[3]])' being compiled

  */
  <MooZ> RzR: push_back needs the = operator to be defined
  <MooZ> so that's why u have an error
  <MooZ> have u tried:
  <MooZ> typedef vfloat3{
  <MooZ>   union {
  <MooZ>     float data[[3]];
  <MooZ>   struct{ float x,y,z; };
  <MooZ> };

  <Doudou> (a propos de la page) le premier probleme, ca marche pas parce que un tableau C et C++ sur un type T est un "T const*" donc b = a ca merde
  <Doudou> Le deuxieme, ca merde pour exactement pour la meme raison.
  <Doudou> std::vector<T> a besoin que T soit "assignable", autrement dit que l'opérateur = soit valide, ce qui n'est pas le cas ici
  <Doudou> std::list, par contre, a juste besoin d'un constructeur par copie. Donc ca marche ..


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