How to cast the size_t to double or int C++

A cast, as Blaz Bratanic suggested:

size_t data = 99999999;
int convertdata = static_cast<int>(data);

is likely to silence the warning (though in principle a compiler can warn about anything it likes, even if there’s a cast).

But it doesn’t solve the problem that the warning was telling you about, namely that a conversion from size_t to int really could overflow.

If at all possible, design your program so you don’t need to convert a size_t value to int. Just store it in a size_t variable (as you’ve already done) and use that.

Converting to double will not cause an overflow, but it could result in a loss of precision for a very large size_t value. Again, it doesn’t make a lot of sense to convert a size_t to a double; you’re still better off keeping the value in a size_t variable.

(R Sahu’s answer has some suggestions if you can’t avoid the cast, such as throwing an exception on overflow.)