pub struct EntropyRng { /* fields omitted */ }
An interface returning random data from external source(s), provided
specifically for securely seeding algorithmic generators (PRNGs).
Where possible, EntropyRng
retrieves random data from the operating
system's interface for random numbers (OsRng
); if that fails it will
fall back to the JitterRng
entropy collector. In the latter case it will
still try to use OsRng
on the next usage.
If no secure source of entropy is available EntropyRng
will panic on use;
i.e. it should never output predictable data.
This is either a little slow (OsRng
requires a system call) or extremely
slow (JitterRng
must use significant CPU time to generate sufficient
jitter); for better performance it is common to seed a local PRNG from
external entropy then primarily use the local PRNG (thread_rng
is
provided as a convenient, local, automatically-seeded CSPRNG).
On most systems, like Windows, Linux, macOS and *BSD on common hardware, it
is highly unlikely for both OsRng
and JitterRng
to fail. But on
combinations like webassembly without Emscripten or stdweb both sources are
unavailable. If both sources fail, only try_fill_bytes
is able to
report the error, and only the one from OsRng
. The other RngCore
methods will panic in case of an error.
Create a new EntropyRng
.
This method will do no system calls or other initialization routines,
those are done on first use. This is done to make new
infallible,
and try_fill_bytes
the only place to report errors.
Formats the value using the given formatter. Read more
Returns the "default value" for a type. Read more
Fill dest
entirely with random data. Read more
Return a random value supporting the [Standard
] distribution. Read more
Generate a random value in the range [low
, high
), i.e. inclusive of low
and exclusive of high
. Read more
Sample a new value, using the given distribution. Read more
Important traits for DistIter<'a, D, R, T>
impl<'a, D, R, T> Iterator for DistIter<'a, D, R, T> where
D: Distribution<T>,
R: Rng + 'a, type Item = T;
[−]
Create an iterator that generates values using the given distribution. Read more
Fill dest
entirely with random bytes (uniform value distribution), where dest
is any type supporting [AsByteSliceMut
], namely slices and arrays over primitive integer types (i8
, i16
, u32
, etc.). Read more
Fill dest
entirely with random bytes (uniform value distribution), where dest
is any type supporting [AsByteSliceMut
], namely slices and arrays over primitive integer types (i8
, i16
, u32
, etc.). Read more
Return a bool with a probability p
of being true. Read more
Return a random element from values
. Read more
Return a mutable pointer to a random element from values
. Read more
Deprecated since 0.5.0
: use Rng::sample_iter(&Standard) instead
Return an iterator that will yield an infinite number of randomly generated items. Read more
[−]
Deprecated since 0.5.0
: use gen_bool instead
Return a bool with a 1 in n chance of true Read more
[−]
Deprecated since 0.5.0
: use sample_iter(&Alphanumeric) instead
Return an iterator of random characters from the set A-Z,a-z,0-9. Read more
[+]
[+]
[+]
type Error = !
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
[−]
🔬 This is a nightly-only experimental API. (try_from
)
[+]
[+]
[+]
type Error = <U as TryFrom<T>>::Error
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
[−]
🔬 This is a nightly-only experimental API. (try_from
)
[+]
[−]
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static