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

 

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::discard_block_engine

Member functions

discard_block_engine::discard_block_engine (C++11)

discard_block_engine::seed (C++11)

discard_block_engine::base (C++11)

Generation

discard_block_engine::operator() (C++11)

discard_block_engine::discard (C++11)

Characteristics

discard_block_engine::min (C++11)

discard_block_engine::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,                 discard_block_engine<>& e );	(1)	(since C++11)
template< class CharT, class Traits > friend std::basic_istream<CharT,Traits>&     operator>>( std::basic_istream<CharT,Traits>& ist,                 discard_block_engine& e );	(2)	(since C++11)

1) Serializes the internal state of the pseudo-random number engine adaptor as a sequence of decimal numbers separated by one or more spaces, and inserts it to the stream ost. The fill character and the formatting flags of the stream are ignored and unaffected.

2) Restores the internal state of the pseudo-random number engine adaptor e from the serialized representation, which was created by an earlier call to operator<< using a stream with the same imbued locale and the same CharT and Traits. If the input cannot be deserialized, e is left unchanged and failbit is raised on ist.

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

If a textual representation is written using os << x and that representation is restored into the same or a different object y of the same type using is >> y, then x==y.

Parameters

ost	-	output stream to insert the data to
ist	-	input stream to extract the data from
e	-	engine adaptor to serialize or restore

Return value

1) ost

2) ist

Exceptions

1) May throw implementation-defined exceptions.

2) May throw std::ios_base::failure when setting failbit.

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	specified to be hidden friends