# Arithmetic overflow: '%operator%' operation causes overflow at compile time. Use a wider type to store the operands

This warning indicates that an arithmetic operation was provably lossy at compile time. This can be asserted when the operands are all compile-time constants. Currently, we check left shift, multiplication, addition, and subtraction operations for such overflows.

Note: C4307 is a similar check in the Microsoft C++ compiler.

## Example 1

```
int multiply()
{
const int a = INT_MAX;
const int b = 2;
int c = a * b; // C26450 reported here
return c;
}
```

To correct this warning, use the following code.

```
long long multiply()
{
const int a = INT_MAX;
const int b = 2;
long long c = (long long)a * b; // OK
return c;
}
```

## Example 2

```
int add()
{
const int a = INT_MAX;
const int b = 2;
int c = a + b; // C26450 reported here
return c;
}
```

To correct this warning, use the following code:

```
long long add()
{
const int a = INT_MAX;
const int b = 2;
long long c = (long long)a + b; // OK
return c;
}
```

## Example 3

```
int subtract()
{
const int a = -INT_MAX;
const int b = 2;
int c = a - b; // C26450 reported here
return c;
}
```

To correct this warning, use the following code.

```
long long subtract()
{
const int a = -INT_MAX;
const int b = 2;
long long c = (long long)a - b; // OK
return c;
}
```