what is malloc in C++

[ayesha shahid]

please help me convert it in C++ language

r->next=(class polynomial *)malloc(sizeof(class polynomial));

help me its urgent

[Frinavale]

malloc is a function that dynamically allocates memory for something.

[weaknessforcats]

malloc in C++ is malloc.

All the C++ new operator does is call the class constructor after doing a malloc to allocate memory.

[Banfa]

And the corollary of weaknessforcats statement is that by just calling malloc as you have done the constructor for the class does not get called, the class is left unconstructed.

Of course you could always call the placement new operator (also note that in your code use of the keyword class is not required). Placement new constructs a class without allocating the data for it, it assumes that the data has already been allocated and you have to provide a buffer of the right size to construct the class in.

void *buffer = malloc(sizeof(polynomial));
r->next = new(buffer) polynomial;

// Destruction - call destructor directly
r->next->~polynomial();

There is almost never any need to do this (I've done it once in 20 years)

If you haven't already it's time to look up the new operator in your favourite C++ text book (or on the net).