tgen::distinct_range< T >

Distinct generator for integral ranges. More...

Public Member Functions
	distinct_range (T left, T right)
	Creates distinct generator for values in given range.
count_type	size () const
	Returns the number of values left to generate.
T	gen ()
	Generates a distinct random value in the defined range.
auto	gen_list (int count)
	Generates a list of several distinct values.
auto	gen_all ()
	Generates all distinct values left to generate.

Detailed Description

template<typename T>
struct tgen::distinct_range< T >

Distinct generator for integral ranges.

Examples

// Prints 3 distinct numbers from 1 to 10, uniformly at random.
tgen::distinct_range u(1, 10);
std::cout << u.gen() << " " << u.gen() << " " << u.gen() << std::endl;

Definition at line 1158 of file tgen.h.

Constructor & Destructor Documentation

distinct_range()

template<typename T>

tgen::distinct_range< T >::distinct_range ( T left, T right )

inline

Creates distinct generator for values in given range.

Parameters

left	Left endpoint of the range.
right	Right endpoint of the range.

The generator will generate values in [l, r].

Examples

// Creates a generator for distinct nubers from 5 to 10.
auto u = tgen::distinct_range(5, 10);

Definition at line 1175 of file tgen.h.

Member Function Documentation

gen()

template<typename T>

T tgen::distinct_range< T >::gen ( )

inline

Generates a distinct random value in the defined range.

Returns

A value in the given range that has not been generated before, uniformly at random.

Exceptions

std::runtime_error

if there no more values to generate.

Time complexity

O(log(n)) for the n-th call of gen.

Examples

// Prints 3 distinct numbers from 1 to 10, uniformly at random.
tgen::distinct_range u(1, 10);
std::cout << u.gen() << " " << u.gen() << " " << u.gen() << std::endl;

Definition at line 1184 of file tgen.h.

gen_all()

template<typename T>

auto tgen::distinct_range< T >::gen_all ( )

inline

Generates all distinct values left to generate.

Returns

A uniformly random tgen::list::value with all distinct values from the range that have not been generated yet.

Exceptions

std::runtime_error

If the remaining count exceeds INT_MAX, the maximum count accepted by distinct_range::gen_list.

Time complexity

Expected O(r), where r is the number of remaining values.

Examples

// Prints all numbers from 1 to 10 in a uniformly random order.
std::cout << tgen::distinct_range(1, 10).gen_all() << std::endl;

Definition at line 1267 of file tgen.h.

gen_list()

template<typename T>

auto tgen::distinct_range< T >::gen_list ( int size )

inline

Generates a list of several distinct values.

Returns

A uniformly random tgen::list::value with size distinct values from the range.

Exceptions

std::runtime_error

if there are not enough values to generate.

Time complexity

Expected O(size), except when first materializing a small remaining range of r values as a dense pool, which costs O(r). Later batches reuse that pool. All draws share state with distinct_range::gen.

Examples

// Prints 3 distinct numbers from 1 to 10, uniformly at random.
std::cout << tgen::distinct_range(1, 10).gen_list(3) << std::endl;

Definition at line 1214 of file tgen.h.

size()

template<typename T>

count_type tgen::distinct_range< T >::size ( ) const

inline

Returns the number of values left to generate.

Returns

The number of values left to generate, as count_type: uint64_t for coordinate types smaller than 64 bits, or unsigned __int128 for 64-bit types. The wider count can represent all 2^64 values of a full 64-bit range.

Time complexity

O(1).

Examples

// Prints current size of distinct generator.
tgen::distinct_range u(5, 10);
u.gen(), u.gen();
std::cout << u.size() << std::endl; // Prints "4".

Definition at line 1179 of file tgen.h.

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The documentation for this struct was generated from the following files:

• /home/runner/work/tgen/tgen/single_include/tgen.h
• base.dox