typedef int aSave[3];
...
aSave *_Save;
...
_Save=new aSave[];
need help : pointer to an array of int
Author
hi
i'm quite desperate as of this moment,
could someone please help me correct the following code:
As you're using C++, make aSave a class:
You can also add bounds checking to the operator []. You'll need to add extra stuff to the class to make it really useful (constructor, assignment, etc).
Skizz
class aSave{public: int &operator [] (int index) { return array [index]; }private: int array [3];};You can also add bounds checking to the operator []. You'll need to add extra stuff to the class to make it really useful (constructor, assignment, etc).
Skizz
Author
Thanks for feedback,
I wanted to make it as simple as possible, but hey, that's a good solution. It's much clearer than the array/pointer mess.
A bit more code to type but who cares.
Big Thanks!
I wanted to make it as simple as possible, but hey, that's a good solution. It's much clearer than the array/pointer mess.
A bit more code to type but who cares.
Big Thanks!
You could end up with something like this:
But the class solution is better I think.
typedef int aSave[3], *aSavePtr;...aSavePtr Save = new aSave;But the class solution is better I think.
Now, if you want to get funky with this, then you could add some template magic:
The above lets us extend and alter the array class by defining a new traits class:
You can also change the types held in the array. This is getting close to what std::vector and similar STL types do - std::vector does dynamic resizing. Quite often you'll find that the STL already implements types that do what you want.
Skizz
#include <algorithm>// the array class templatetemplate <class T, int size, class trait = default_array_trait>class generic_array{public: generic_array (void) { std::fill (m_array, &m_array [size], 0); } T &operator [] (int index) { return m_array [trait::check_index (index, size)]; }private: T m_array [size];};// this class is used to check the index used in the generic_array operator [] functionclass default_array_trait{public: static int check_index (int index, int size) { return index >= 0 && index < size ? index : 0; }};// define a type that contains 3 integerstypedef generic_array<int, 3> simple_array;void f1 (void){ // example of using above type simple_array an_array; an_array [0] = 42;}The above lets us extend and alter the array class by defining a new traits class:
template <int lower_bounds>class bounded_array_trait{public: static int check_index (int index, int size) { return index >= lower_bounds && index < (lower_bounds + size) ? index - lower_bounds : 0; }};// define a type that contains 10 integers starting at index 100typedef generic_array <int, 10, bounded_array_trait <100> > bounded_array;void f2 (void){ // example of using above type bounded_array an_array; an_array [100] = 42;}You can also change the types held in the array. This is getting close to what std::vector and similar STL types do - std::vector does dynamic resizing. Quite often you'll find that the STL already implements types that do what you want.
Skizz
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