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Re: Wading through template instantiation errors for allocator

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On 1/4/2020 11:34 PM, Frederick Gotham wrote:
> Bo wrote:
> 
>> rebind is only optional (provided by std::allocator_traits) if this
>> allocator is a template of the form SomeAllocator<T, Args>, where Args
>> is zero or more additional template type parameters."
> 
> 
> Well spotted. Here's my workaround:
> 
> 
> #include <cstddef>  /* size_t */
> #include <new> /* Only for bad_alloc */
> 
> template <std::size_t capacity>
> class Outer {
> 
> template<typename T>
> class StaticAllocator {
> public:
>          typedef T value_type;
> 
> protected:
> 
>          static T buf[capacity];
> 
> public:
> 
>          T *allocate(std::size_t const n)
>          {
>                  if (n > capacity)
>                          throw std::bad_alloc();
> 
>                  return buf;
>          }
> 
>          void deallocate(T *, std::size_t)
>          {
>                  /* Do Nothing */
>          }
> };
> 
> };
> 
> template<std::size_t capacity>
> template<typename T>
> T Outer<capacity>::StaticAllocator<T>::buf[capacity];
> 
> using std::size_t;
> 
> #include <vector>
> using std::vector;
> 
> #include <iostream>
> using std::cout;
> using std::endl;
> 
> auto main(void) -> int
> {
>          vector< char, Outer<4>::StaticAllocator<char> > v;
> 
>          v.push_back('a');
>          v.push_back('b');
>          v.push_back('c');
>          v.push_back('d');
> 
>          for (auto const &elem : v)
>                  cout << elem << endl;
>              
>          vector< char, Outer<4>::StaticAllocator<char> > v2;
> 
>          v2.push_back('x');
>          v2.push_back('y');
>          v2.push_back('z');
> 
>          for (auto const &elem : v2)
>                  cout << elem << endl;
>                  
>          // Now try the first vector again
>          
>          for (auto const &elem : v)
>                  cout << elem << endl;
> }
> 
> 
> Now I can get back to testing my new allocator.
> 

The following satisfies the rebind requirement, although I do not know 
how this may play in a more elaborate context:

template<typename T, std::size_t capacity>
class StaticAllocator {
   public:
     typedef T value_type;

   protected:

     static T buf[capacity];

   public:

     template<typename U>
       struct rebind
       {
         typedef StaticAllocator<U, capacity> other;
       };

     T *allocate(std::size_t const n)
     {
       if (n > capacity)
         throw std::bad_alloc();

       return buf;
     }

     void deallocate(T *, std::size_t)
     {
       /* Do Nothing */
     }
};

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Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-03 07:04 -0800
  Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-03 16:57 +0000
  Re: Wading through template instantiation errors for allocator Paavo Helde <myfirstname@osa.pri.ee> - 2020-01-03 21:32 +0200
    Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-04 06:12 -0800
      Re: Wading through template instantiation errors for allocator Bo Persson <bo@bo-persson.se> - 2020-01-04 15:53 +0100
        Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-04 14:34 -0800
          Re: Wading through template instantiation errors for allocator Manfred <noname@add.invalid> - 2020-01-05 22:31 +0100
  Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-06 02:12 -0800
    Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-06 23:52 -0800
  Re: Wading through template instantiation errors for allocator Ian Collins <ian-news@hotmail.com> - 2020-01-07 21:15 +1300
    Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-07 01:01 -0800
      Re: Wading through template instantiation errors for allocator Ian Collins <ian-news@hotmail.com> - 2020-01-08 07:31 +1300
        Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 19:50 +0100
        Re: Wading through template instantiation errors for allocator Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-01-10 07:06 -0800
          Re: Wading through template instantiation errors for allocator Frederick Gotham <cauldwell.thomas@gmail.com> - 2020-01-14 02:25 -0800
    Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 09:20 +0000
    Re: Wading through template instantiation errors for allocator boltar@nowhere.org - 2020-01-08 10:12 +0000
    Re: Wading through template instantiation errors for allocator Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-01-08 09:22 -0800
      Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-08 17:44 +0000
      Re: Wading through template instantiation errors for allocator "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2020-01-08 23:00 +0100
    Re: Wading through template instantiation errors for allocator Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-01-10 06:48 -0800
  Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 09:20 +0000
    Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 09:35 +0000
      Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 09:43 +0000
        Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 10:47 +0100
          Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 10:59 +0100
            Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 10:15 +0000
              Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 11:21 +0100
                Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 10:25 +0000
          Re: Wading through template instantiation errors for allocator Melzzzzz <Melzzzzz@zzzzz.com> - 2020-01-07 10:02 +0000
          Re: Wading through template instantiation errors for allocator Bo Persson <bo@bo-persson.se> - 2020-01-07 15:27 +0100
  Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 10:36 +0100
    Re: Wading through template instantiation errors for allocator Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-07 10:42 +0100

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