DynArray.h

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#ifndef CommonTools_Utils_DynArray_H
#define CommonTools_Utils_DynArray_H

template<typename T>
class DynArray {
public:
   T * a=nullptr;
   unsigned int s=0;
public :
   using size_type = unsigned int;
   using value_type = T;
   using reference = T&;
   using const_reference = T const&;

  DynArray(){}

  explicit DynArray(unsigned char * storage) : a((T*)(storage)), s(0){}

  DynArray(unsigned char * storage, unsigned int isize) : a((T*)(storage)), s(isize){
    for (auto i=0U; i<s; ++i) new((begin()+i)) T();
  }
  DynArray(unsigned char * storage, unsigned int isize, T const& it) : a((T*)(storage)), s(isize){
    for (auto i=0U; i<s; ++i) new((begin()+i)) T(it);
  }

  DynArray(DynArray const&) = delete;
  DynArray & operator=(DynArray const &) = delete;

  DynArray(DynArray && other) { a=other.a; s=other.s; other.s=0; other.a=nullptr;}
  DynArray & operator=(DynArray && other) { a=other.a; s=other.s; other.s=0; other.a=nullptr; return *this;}


  ~DynArray() { for (auto i=0U; i<s; ++i) a[i].~T(); }

   T & operator[](unsigned int i) { return a[i];}
   T * begin() { return a;}
   T * end() { return a+s;}
   T & front() { return a[0];}
   T & back() { return a[s-1];}

   T const & operator[](unsigned int i) const { return a[i];}
   T const * begin() const { return a;}
   T const * end() const { return a+s;}
   unsigned int size() const { return s;}
   bool empty() const { return 0==s;}

   T const &front() const { return a[0];}
   T const & back() const { return a[s-1];}

   void pop_back() {back().~T(); --s;}
   void push_back(T const& t) {new((begin()+s)) T(t);++s;}
   void push_back(T && t) {new((begin()+s)) T(t);++s;}


};

#define unInitDynArray(T,n,x)  alignas(alignof(T)) unsigned char x ## _storage[sizeof(T)*n]; DynArray<T> x(x ## _storage)
#define declareDynArray(T,n,x)  alignas(alignof(T)) unsigned char x ## _storage[sizeof(T)*n]; DynArray<T> x(x ## _storage,n)
#define initDynArray(T,n,x,i)  alignas(alignof(T)) unsigned char x ## _storage[sizeof(T)*n]; DynArray<T> x(x ## _storage,n,i)


#endif // CommonTools_Utils_DynArray_H