c++ - Fixed Allocator with stack - how to implement allocate and deallocate? -

i've started code fixedallocator class allocates memory chunks of fixed size , works stack, works in constant time allocate/deallocate. actually, i'll need class use std::vector, have implement std::allocator methods.

everything here learning purposes - don't need complete implementations or headers - real ones have lot of code on problem.

and got stuck on allocate/deallocate methods - understand should somehow reserve memory pool - example using vector, understand should use static_cast convert char type t-type, don't understand how rebuild 2 ideas list. deallocate takes pointer argument, not tnode - that's maybe main problem.

if wrote kind of allocator - answer code perfect. suggestions, links , other source of knowledge welcome. thank you.

here skeleton of code:

template <typename t, unsigned int nodesize>  class fixedallocator : public std::allocator<t>{ private:     static size_t used;     static const size_t max_size = 100000;  struct tnode {     tnode* next;     char data[nodesize]; };  tnode* head;  public: typedef t* pointer; typedef const t* const_pointer; typedef t & reference; typedef const t & const_reference; typedef t value_type; template <typename u> struct rebind { typedef allocator<u> other; };  fixedallocator() {     if (pool.empty()) {         pool.resize(max_size * sizeof(t));         used = 0;     }    }  fixedallocator(const fixedallocator &) { }  template<typename u> fixedallocator(const fixedallocator<u> &) {     if (pool.empty()) {         pool.resize(max_size * sizeof(t));         used = 0;     } }  pointer address(reference x) const {     return &x; }  const_pointer address(const_reference x) const {     return &x; }  pointer allocate(size_t n, fixedallocator<void>::const_pointer = 0) {}  void deallocate(pointer, size_t) {}  size_t max_size() const throw() {     return max_size - size; }  void construct(pointer p, const_reference val) {     new (static_cast<void*>(p)) value_type(val); }  void destroy(pointer p) {     p->~value_type(); } };