Compiler error: invalid conversion from 'int' to 'int*' [-fpermissive]|

Question

I got a compiler error:

main.cpp|59|error: invalid conversion from \'int\' to \'int*\' [-fpermissive]|

The offending line is

Answer 1

Your error is in this line:

int *pComienzo = vector, *pFinal = vector[nElementos-1];

The reason for this is that vector is an int*, but vector[nElementos - 1] is a regular int. Thus the declaration

int *pFinal = vector[nElementos - 1];

is trying to assign the integer value at the last index of vector to the pointer pFinal, hence the compiler error.

To fix this, you may want to do either

int *pFinal = &vector[nElementos - 1];

which makes pFinal point to the last element of vector, or

int *pFinal = vector + (nElementos - 1);

which accomplishes the same thing using pointer arithmetic.

That said, since you're working in C++, why not use the provided std::vector type and avoid working with pointers altogether?

Hope this helps!

Answer 2

vector is a pointer, but subscripting it as vector[nElementos-1] dereferences it to simply an int. What it looks like you want is instead

int *pComienzo = vector, *pFinal = &(vector[nElementos-1]);

Answer 3

An array access/subscript (i.e., a[i] where a is an array/pointer and i is an integer) is an expression with the type being the thing you have in the array.

Simply use the address-of operator & to store the address in the pointer:

int *pComienzo = vector, *pFinal = &vector[nElementos-1];

Answer 4

You forgot &. vector[nElementos-1] is the value, while you need an address for pFinal.

Either *pFinal = &(vector[nElementos-1]) or *pFinal = vector + nElementos-1.