28
Numerics library
[numerics]
28.5
Random number generation
[rand]
28.5.9
Random number distribution class templates
[rand.dist]
28.5.9.3
Bernoulli distributions
[rand.dist.bern]
28.5.9.3.1
Class
bernoulli_
distribution
[rand.dist.bern.bernoulli]
1
#
A
bernoulli_
distribution
random number distribution produces
bool
values
b
distributed according to the discrete probability function in Formula
28.4
.
P
(
b
|
p
)
=
{
p
if
b
=
true
1
−
p
if
b
=
false
(28.4)
🔗
namespace
std
{
class
bernoulli_distribution
{
public
:
// types
using
result_type
=
bool
;
using
param_type
=
unspecified
;
// constructors and reset functions
bernoulli_distribution
(
)
:
bernoulli_distribution
(
0.5
)
{
}
explicit
bernoulli_distribution
(
double
p
)
;
explicit
bernoulli_distribution
(
const
param_type
&
parm
)
;
void
reset
(
)
;
// equality operators
friend
bool
operator
=
=
(
const
bernoulli_distribution
&
x,
const
bernoulli_distribution
&
y
)
;
// generating functions
template
<
class
URBG
>
result_type
operator
(
)
(
URBG
&
g
)
;
template
<
class
URBG
>
result_type
operator
(
)
(
URBG
&
g,
const
param_type
&
parm
)
;
// property functions
double
p
(
)
const
; param_type param
(
)
const
;
void
param
(
const
param_type
&
parm
)
; result_type min
(
)
const
; result_type max
(
)
const
;
// inserters and extractors
template
<
class
charT,
class
traits
>
friend
basic_ostream
<
charT, traits
>
&
operator
<
<
(
basic_ostream
<
charT, traits
>
&
os,
const
bernoulli_distribution
&
x
)
;
template
<
class
charT,
class
traits
>
friend
basic_istream
<
charT, traits
>
&
operator
>
>
(
basic_istream
<
charT, traits
>
&
is, bernoulli_distribution
&
x
)
;
}
;
}
🔗
explicit
bernoulli_distribution
(
double
p
)
;
2
#
Preconditions
:
0 ≤
p
≤ 1
.
3
#
Remarks
:
p
corresponds to the parameter of the distribution
.
🔗
double
p
(
)
const
;
4
#
Returns
: The value of the
p
parameter with which the object was constructed
.