#
LongDoubleConversion

Conversion from long to double may lose precision; use an explicit cast to double if this was intentional

## The problem

A cast from `long`

to `double`

may lose precision. Prefer an explicit cast to an
implicit conversion if this was intentional.

Consider
`com.google.protobuf.util.Values`

which has a method `of(double value)`

, and the following example:

```
// Values.of receives a long, which is implicitly converted to double:
long value = 123L;
Values.of(value);
```

Prefer this (to make existing behavior explicit):

```
long value = 123L;
Values.of((double) value);
```

From JLS ยง5.1.2:

A widening primitive conversion from `int`

to `float`

, or from `long`

to
`float`

, or from `long`

to `double`

, may result in loss of precision - that
is, the result may lose some of the least significant bits of the value. In
this case, the resulting floating-point value will be a correctly rounded
version of the integer value, using IEEE 754 round-to-nearest mode

## Suppression

Suppress false positives by adding the suppression annotation `@SuppressWarnings("LongDoubleConversion")`

to the enclosing element.