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int64.go
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int64.go
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package easyrand
import (
"crypto/rand"
)
func Int64() (int64, error) {
b := make([]byte, 8)
if _, err := rand.Read(b); err != nil {
return 0, err
}
return int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 |
int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56, nil
}
func Int64Range(min, max int64) (int64, error) {
d := max - min
if d == 0 {
return min, nil
}
x, err := Int64()
if err != nil {
return 0, err
}
//XXX: x should always be positive
x &= int64(^(uint64(1) << 63))
return min + (x % d), nil
}
func Int64Checked() int64 {
x, err := Int64()
if err != nil {
panic(err)
}
return x
}
func Int64RangeChecked(min, max int64) int64 {
x, err := Int64Range(min, max)
if err != nil {
panic(err)
}
return x
}
func Int64Unchecked() int64 {
x, _ := Int64()
return x
}
func Int64RangeUnchecked(min, max int64) int64 {
x, _ := Int64Range(min, max)
return x
}