Allocators

• Allocators required in environments with multiple memory models (16 bit PCs).

• Allocators may also be useful for fixed-memory applications, OO database interfaces, and parallel processing.

• Kludge! Every STL container class is supposed to be parameterized with an allocator template class (with a default value). For example, list should be declared as:

     template < class T, template < class U > Alloc = alloctor >
     class list { ...
     

  So you can declare a list either way:

     list< int > a;
     list< int, far_allocator > b;
     

  But most compiler don't yet support default template arguments that are templates themsleves. So the kludge is that the allocator is handled by the preprocessor. Very limiting.