y = i/double(7);       //would do division
// in double
ptr = (char*)(i + 88); //int to pointer value   

These older forms are considered obsolete. Many older compilers and older source code use them, but they should be replaced by the use of static_cast whenever possible.

Occasionally, you need to store a value into a variable of a different type. Whenever there is the risk of information loss, the compiler issues a warning. For example, if you store a double value into an int variable, you can lose information in two ways:

1. The fractional part is lost.
2. The magnitude may be too large.

For example,

int p = 1.0E100; // NO

is not likely to work, because 10¹⁰⁰ is larger than the largest representable integer

Nevertheless, sometimes you do want to convert a floating-point value into an integer value. If you are prepared to lose the fractional part and you know that this particular floating-point number is not larger than the largest possible integer, then you can turn off the warning by using a cast.
Cast: a conversion from one type (such as double) to another type (such as int) that is not safe in general, but that you know to be safe in a particular circumstance.
You express this in C++ as follows:

int n = static_cast < int >(y + 0.5);

int n = (int)(y + 0.5);

static_cast<type_name>(expression)

static_cast<int>(x + 0.5)