sizeof dynamic allocation

When i allocate dynamically a char* of 256 array for example, i thought that its size is 256 bytes.
But sizeof() always gives back the size of a char*.
So how would i go to get the size allocated?

Code:

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#include <iostream>

using namespace std;

int  main()
{
    char * buf = new char[256];
    cout << sizeof(buf) <<"\n";
    delete [] buf;
 
    return  0;
}

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Use another variable.

Or use a "smart" container like std::string (in particular for chars) or std::vector

Ok, now i start to understand the differences between C and C++. :)

Thanks!

sizeof cannot determine the size of memory pointed to by a pointer. It only works with arrays.

Quote:

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Originally Posted by Ducky

Ok, now i start to understand differences between C and C++. :)

Thanks!

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Yeah, C++ programmers cant do anything for themselves. Just joking I like C++.

If you know the size of the buffer then you can use:

Code:

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sizeof(char) * buffer_size

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However the suggestion of using a smart container is much better.

Quote:

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Originally Posted by ryanrigdon

If you know the size of the buffer then you can use:

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The point is to "know" the size. :)

If you already know it why would you use anything? :)