Memory

A recreation of the standard <memory> header, for high-level memory manipulation. While a surprising amount of the modern header relies on variadic templates, some if it can be safely reimplemented into C++98.

Note that this header includes shared_ptr and scoped_ptr.

As the memory header itself is very comprehensive, these pointers are offered separately from the core functions which were reimplemented, in an attempt to prevent the entire memory header from slowing compile times for users who only really want to use a smart pointer.

Features

Included headers:

shared_ptr	A copyable, reference-counted smart pointer type, with support types included
scoped_ptr	A simple, uncopyable, scoped-based smart pointer which models unique ownership

Functionality:

pointer_traits	Provides general information about pointer types
uses_allocator	Checks if the specified type supports "uses-allocator" construction
to_address	Obtains a raw pointer from an applicable pointer type
addressof	Obtains the address of an object, even if operator& is overloaded
uninitialized_copy_n	Copies a number of elements into uninitialized memory
uninitialized_default_construct	Default-constructs objects into a region of uninitialised memory, by range
uninitialized_default_construct_n	Default-constructs a number of objects into a region of uninitialised memory
uninitialized_value_construct	Value-constructs objects into a region of uninitialised memory, by range
uninitialized_value_construct_n	Value-constructs a number of objects into a region of uninitialised memory.
destroy_at	Destroys the object at a given address
destroy	Destroys a range of objects
destroy_n	Destroys a number of objects

Sample code

#include <iostream>
#include "cpp98/memory.h"
 
template<class T>
struct Ptr
{
    T* pad; // add pad to show difference between 'this' and 'data'
    T* data;
    Ptr(T* arg) : pad(NULL), data(arg)
    {
        std::cout << "Ctor this = " << this << '\n';
    }
 
    ~Ptr() { delete data; }
    T** operator&() { return &data; }
};
 
template<class T>
void f(Ptr<T>* p)
{
    std::cout << "Ptr   overload called with p = " << p << '\n';
}
 
void f(int** p)
{
    std::cout << "int** overload called with p = " << p << '\n';
}
 
int main()
{
    Ptr<int> p(new int(42));
    f(&p);                // calls int** overload
    f(dp::addressof(p)); // calls Ptr<int>* overload, (= this)
}