operator<<,>>(std::exponential_distribution)

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Numerics library

Common mathematical functions

Mathematical special functions (C++17)

Mathematical constants (C++20)

Floating-point environment (C++11)

Complex numbers

Numeric arrays

Pseudo-random number generation

Factor operations

gcd (C++17)

lcm (C++17)

Interpolations

midpoint (C++20)

lerp (C++20)

Generic numeric operations

iota (C++11)

ranges::iota (C++23)

accumulate

inner_product

adjacent_difference

partial_sum

reduce (C++17)

transform_reduce (C++17)

inclusive_scan (C++17)

exclusive_scan (C++17)

transform_inclusive_scan (C++17)

transform_exclusive_scan (C++17)

Bit operations

bit_cast (C++20)

byteswap (C++23)

has_single_bit (C++20)

bit_ceil (C++20)

bit_floor (C++20)

bit_width (C++20)

rotl (C++20)

rotr (C++20)

countl_zero (C++20)

countl_one (C++20)

countr_zero (C++20)

countr_one (C++20)

popcount (C++20)

endian (C++20)

 

Pseudo-random number generation

Uniform random bit generators

uniform_random_bit_generator (C++20)

Engines and engine adaptors

linear_congruential_engine (C++11)

mersenne_twister_engine (C++11)

subtract_with_carry_engine (C++11)

discard_block_engine (C++11)

independent_bits_engine (C++11)

shuffle_order_engine (C++11)

Non-deterministic generator

random_device (C++11)

Distributions

Uniform distributions

uniform_int_distribution (C++11)

uniform_real_distribution (C++11)

generate_canonical (C++11)

Bernoulli distributions

bernoulli_distribution (C++11)

binomial_distribution (C++11)

negative_binomial_distribution (C++11)

geometric_distribution (C++11)

Poisson distributions

poisson_distribution (C++11)

exponential_distribution (C++11)

gamma_distribution (C++11)

weibull_distribution (C++11)

extreme_value_distribution (C++11)

Normal distributions

normal_distribution (C++11)

lognormal_distribution (C++11)

chi_squared_distribution (C++11)

cauchy_distribution (C++11)

fisher_f_distribution (C++11)

student_t_distribution (C++11)

Sampling distributions

discrete_distribution (C++11)

piecewise_constant_distribution (C++11)

piecewise_linear_distribution (C++11)

Seed Sequences

seed_seq (C++11)

C library

rand

srand

RAND_MAX

 

std::exponential_distribution

Member functions

exponential_distribution::exponential_distribution (C++11)

exponential_distribution::reset (C++11)

Generation

exponential_distribution::operator() (C++11)

Characteristics

exponential_distribution::lambda (C++11)

exponential_distribution::param (C++11)

exponential_distribution::min (C++11)

exponential_distribution::max (C++11)

Non-member functions

operator==operator!= (C++11)(C++11)(until C++20)

operator<<operator>> (C++11)(C++11)

 

template< class CharT, class Traits > friend std::basic_ostream<CharT,Traits>&     operator<<( std::basic_ostream<CharT,Traits>& ost,                 const exponential_distribution& d );	(1)	(since C++11)
template< class CharT, class Traits > friend std::basic_istream<CharT,Traits>&     operator>>( std::basic_istream<CharT,Traits>& ist,                 exponential_distribution& d );	(2)	(since C++11)

Performs stream input and output operations on pseudo-random number distribution d.

1) Writes a textual representation of the distribution parameters and internal state to ost as textual representation. The formatting flags and fill character of ost are unchanged.

2) Restores the distribution parameters and internal state with data read from ist. The formatting flags of ist are unchanged. The data must have been written using a stream with the same locale, CharT and Traits template parameters, otherwise the behavior is undefined. If bad input is encountered, ist.setstate(std::ios::failbit) is called, which may throw std::ios_base::failure. d is unchanged in that case.

These function templates are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::exponential_distribution<ResultType> is an associated class of the arguments.

Parameters

ost	-	output stream to insert the data to
ist	-	input stream to extract the data from
d	-	pseudo-random number distribution

Return value

1) ost

2) ist

Exceptions

1) May throw implementation-defined exceptions.

2) May throw std::ios_base::failure on bad input.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 3519	C++11	the form of insertion and extraction operators were unspecified (could be hidden friends or out-of-class function templates)	specified to be hidden friends