CODEWITHSUNDEEP
c++typeinfo
Maxpm
Maxpm

Reputation: 25642

Storing Datatype Information

Let's say I have a few variables of different types.

int MyInteger;
double MyDouble;
char MyChar;

Pointers to these variables are stored in a single array of void pointers.

void* IntegerPointer = &MyInteger;
void* DoublePointer = &MyDouble;
void* CharPointer = &MyChar;

void* PointerArray[] = {IntegerPointer, DoublePointer, CharPointer};

I'd like to store the datatype information in a parallel array. type_info seems to be suited to the task, but assignment isn't supported. So I can't just do something like this:

type_info TypeInfoArray[] = {int, double, char};

Is there any other way to store information about a datatype?

Upvotes: 2

Views: 1574

Answers (4)

BR41N-FCK
BR41N-FCK

Reputation: 766

A tuple would also do the job.

std::tuple<int*,float*> tp (&yourInt, &yourFloat);

Upvotes: 0

Nim
Nim

Reputation: 33655

If you are looking for a container to hold a sequence of different types, look no further than boost::fusion.

For example, if you use a fusion sequence for your types, 

fusion::vector<int, double, char> object_array(1, 2.0, 'F');

Now, to get what's at index 0 for example

at<0>(object_array); // will provide a reference to the int field

It's perfectly type safe, and not a void * in sight... The only downside is that there is a limit to the number of "elements" you can have in the sequence (typically the number of template parameters as enforced by the compiler).

Upvotes: 0

Steve
Steve

Reputation: 1810

I suggest you use a variant type. I hate to say it, but try boost::variant (or something similar). Forget all this parallel array and void pointer stuff; a single array of variants achieves the same thing and is more elegant.

Upvotes: 6

BЈовић
BЈовић

Reputation: 64293

Take a look at typeinfo. Then you can store type info as an array of std::string

Upvotes: 2

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