std::discard_block_engine

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Numerics library

Common mathematical functions
Mathematical special functions(C++17)
Mathematical constants(C++20)
Basic linear algebra algorithms(C++26)
Data-parallel types (SIMD)(C++26)
Floating-point environment(C++11)
Complex numbers
Numeric array (valarray)
Pseudo-random number generation
Bit manipulation(C++20)
Saturation arithmetic(C++26)
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)
C-style checked integer arithmetic
ckd_add (C++26) ckd_sub (C++26)	ckd_mul (C++26)

 

Pseudo-random number generation

Uniform random bit generators   uniform_random_bit_generator (C++20) Random number engines linear_congruential_engine (C++11) mersenne_twister_engine (C++11) subtract_with_carry_engine (C++11) philox_engine (C++26) Random number engine adaptors discard_block_engine (C++11) independent_bits_engine (C++11) shuffle_order_engine (C++11) Predefined random number generators Non-deterministic random numbers random_device (C++11) Utilities generate_canonical (C++11) seed_seq (C++11) Random number algorithms ranges::generate_random (C++26) C random library rand    srand    RAND_MAX

Random number 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)

 

std::discard_block_engine

Member functions

discard_block_engine::discard_block_engine

discard_block_engine::seed

discard_block_engine::base

Generation

discard_block_engine::operator()

discard_block_engine::discard

Characteristics

discard_block_engine::min

discard_block_engine::max

Non-member functions

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

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

 

Defined in header <random>
template<     class Engine,     std::size_t P, std::size_t R >class discard_block_engine;		(since C++11)

discard_block_engine is a pseudo-random number engine adaptor that discards a certain amount of data produced by the base engine. From each block of size P generated by the base engine, the adaptor keeps only R numbers, discarding the rest.

Template parameters

Engine	-	the type of the wrapped engine.
P	-	the size of a block. Expected that \(\small{P>0}\)P > 0.
R	-	the number of used numbers per block. Expected that \(\small{0<R\le P}\)0 < R ≤ P.
Type requirements
- Engine must meet the requirements of RandomNumberEngine.

Member types

Member type	Definition
result_type(C++11)	Engine::result_type

Member functions

(constructor) (C++11)	constructs the engine adaptor (public member function)
seed (C++11)	sets the state of the underlying engine (public member function)
base (C++11)	returns the underlying engine (public member function)
Generation
operator() (C++11)	advances the state of the underlying engine and returns the generated value (public member function)
discard (C++11)	advances the adaptor's state by a specified amount (public member function)
Characteristics
min [static](C++11)	gets the smallest possible value in the output range of the underlying engine. (public static member function)
max [static](C++11)	gets the largest possible value in the output range of the underlying engine. (public static member function)

Non-member functions

operator==operator!= (C++11)(C++11)(removed in C++20)	compares the internal states of the adaptors and underlying engines (function)
operator<<operator>> (C++11)	performs stream input and output on pseudo-random number engine adaptor (function)

Member constants

constexpr size_t block_size [static](C++11)	the size of the block, P (public static member constant)
constexpr size_t used_block [static](C++11)	the number of used numbers per block, R (public static member constant)