View source code
Display the source code in std/random.d from which this page was generated on github.
Report a bug
If you spot a problem with this page, click here to create a Bugzilla issue.
Improve this page
Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using local clone.

Function std.random.choice

Returns a random, uniformly chosen, element e from the supplied Range range. If no random number generator is passed, the default rndGen is used.

ref auto choice(Range, RandomGen) (
  auto ref Range range,
  ref RandomGen urng
)
if (isRandomAccessRange!Range && hasLength!Range && isUniformRNG!RandomGen);

ref auto choice(Range) (
  auto ref Range range
);

Parameters

NameDescription
range a random access range that has the length property defined
urng (optional) random number generator to use; if not specified, defaults to rndGen

Returns

A single random element drawn from the range. If it can, it will return a ref to the range element, otherwise it will return a copy.

Example

auto rnd = MinstdRand0(42);

auto elem  = [1, 2, 3, 4, 5].choice(rnd);
version (X86_64) // https://issues.dlang.org/show_bug.cgi?id=15147
writeln(elem); // 3

Authors

Andrei Alexandrescu Masahiro Nakagawa (Xorshift random generator) Joseph Rushton Wakeling (Algorithm D for random sampling) Ilya Yaroshenko (Mersenne Twister implementation, adapted from mir-random)

License

Boost License 1.0.