/
12-14.cpp
183 lines (144 loc) · 4.26 KB
/
12-14.cpp
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#include <iostream>
#include <memory>
#include <algorithm>
#include <string>
#include <array>
using std::allocator;
using std::cout;
using std::endl;
using std::max;
using std::uninitialized_copy;
using std::uninitialized_fill;
using std::ptrdiff_t;
using std::string;
using std::array;
template <class T> class Vec {
public:
typedef T* iterator;
typedef const T* const_iterator;
typedef size_t size_type;
typedef T value_type;
typedef T& reference;
typedef const T& const_reference;
Vec() { create(); } // default constructor
explicit Vec(size_type n, const T& t = T()) { create(n, t); }
Vec(const Vec& v) { create(v.begin(), v.end()); } // copy constructor
Vec(string s)
{
string::size_type length = s.size();
data = alloc.allocate(length);
limit = avail = uninitialized_copy(s.begin(), s.end(), data);
}
Vec& operator=(const Vec&);
~Vec() {uncreate(); }
T& operator[](size_type i) { return data[i]; }
const T& operator[](size_type i) const { return data[i]; }
void push_back(const T& t) {
if (avail == limit)
grow();
unchecked_append(t);
}
void insert(iterator pos, iterator first, iterator last) {
size_type delta = last - first;
// grow Vec size enough to incorporate the additional range
while ((limit - avail) < delta)
grow();
// initialize current as the object at the back of Vec
iterator currentO = avail-1;
iterator currentN = last-1;
// invariant: currentO is the back-most object in Vec that has not been
// ovewritten with the new range.
while (currentO >= pos) {
alloc.construct(currentO+delta, *currentO);
*currentO = *currentN;
if (currentO == begin() || currentN == first)
break;
else {
--currentO;
--currentN;
}
}
avail = avail + delta;
}
// assign for an array input
template <class inputIterator>
void assign(inputIterator start, inputIterator term) {
size_type nLength = term - start;
iterator current; // iterator for Vec object
current = data;
while((limit - data) < nLength)
grow();
// iterate through array input
for (inputIterator it = start; it != term; it++) {
if (current >= avail)
unchecked_append(*it);
else
*current = *it;
current++;
}
}
size_type size() const { return avail - data; }
iterator begin() { return data; }
const_iterator begin() const { return data; }
iterator end() { return avail; }
const_iterator end() const { return avail; }
void uncreate();
private:
iterator data;
iterator avail;
iterator limit;
allocator<T> alloc;
void create();
void create(size_type, const T&);
void create(const_iterator, const_iterator);
void grow();
void unchecked_append(const T&);
};
template <class T> void Vec<T>::create()
{
data = avail = limit = 0;
}
template <class T> void Vec<T>::create(size_type n, const T& val)
{
data = alloc.allocate(n);
limit = avail = data + n;
uninitialized_fill(data, limit, val);
}
template <class T>
void Vec<T>::create(const_iterator i, const_iterator j)
{
data = alloc.allocate(j - i);
limit = avail = uninitialized_copy(i, j, data);
}
template <class T> void Vec<T>::uncreate()
{
if (data) {
iterator it = avail;
while (it != data)
alloc.destroy(--it);
alloc.deallocate(data, limit - data);
}
data = limit = avail = 0;
}
template <class T> void Vec<T>::grow()
{
size_type new_size = max(2 * (limit - data), ptrdiff_t(1));
iterator new_data = alloc.allocate(new_size);
iterator new_avail = uninitialized_copy(data, avail, new_data);
uncreate();
data = new_data;
avail = new_avail;
limit = data + new_size;
}
template <class T> void Vec<T>::unchecked_append(const T& val)
{
alloc.construct(avail++, val);
}
int main()
{
string sTerm = "fireroad";
Vec<char> term(sTerm);
for (Vec<char>::iterator it = term.begin(); it != term.end(); it++)
cout << *it << endl;
return 0;
}