Re: Silver bullet for C++ memory management ?
MN wrote:
I've been using smart pointer to save my efforts on dealing with
memory management in C++.
Good idea.
//////// begin of code /////////
#define PtrOf(X) boost::shared_ptr < X >
Not a good idea at all. The macro buys you nothing, except the chance of
ruining unrelated code. Macros should be avoided wherever a better
alternative exists, and if they are used, the should be in all-uppercase
to avoid name clashes.
...
class Animal {
public:
Animal(const std::string& name) { _name = name; }
private:
std::string _name;
};
...
PtrOf(Animal) animal(new Cow());
...
//////// end of code /////////
It has been worked well, however there are two ugly problems:
1) If we put the macro in a class interface, it's really ugly and
obstruct the clarity of the interface.
class Farm {
public:
Farm(PtrOf(Animal) a);
};
Forget about the macro. If you just want to shorten the type name, use a
typedef:
typedef boost::shared_ptr<Animal> AnimalPtr
Then you can use:
Farm(AnimalPtr a);
2. More seriously, if we have to use some 3rd party libraries which do
not use the same convention, instead using bare pointer, we have a
bigger problem to deal with.
There is no silver bullet against bad interfaces. When a third-party
library insists on ownership transfer via raw pointers, you either have
to live with it, or look for a better library. Note that you can still
use smart pointers in your own code and release them only at the point
where ownership passes to the library. Also note that the appearance of
a raw pointer in an interface by itself does not mean that ownership is
transferred. Consult the documentation to learn what the library
actually does with the object to which the raw pointer points.
My question is whether there is a way to address C++ memory management
to reduce it to a painless task ( as Java and C# ) without using 3rd
party garbage collector ?
1. Avoid heap allocation where it is not necessary.
2. Use smart pointers where it is necessary.
3. Use diligence and caution where neither 1 nor 2 are an option.
--
Gerhard Menzl
Non-spammers may respond to my email address, which is composed of my
full name, separated by a dot, followed by at, followed by "fwz",
followed by a dot, followed by "aero".
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