blob: 1dab9ac0894b921cbbcb49005537da4f626144ec [file] [log] [blame]
* 25.random.shuffle.cpp - test exercising 25.2.11 [lib.alg.random.shuffle]
* $Id$
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* implied. See the License for the specific language governing
* permissions and limitations under the License.
* Copyright 1994-2006 Rogue Wave Software.
#include <algorithm> // for random_shuffle
#include <cstring> // for memset(), size_t
#include <alg_test.h>
#include <rw_value.h> // for UserClass
#include <driver.h> // for rw_test()
// disable explicit instantiation for compilers (like MSVC)
// that can't handle it
random_shuffle (RandomAccessIter<assign<base<cpy_ctor> > >,
RandomAccessIter<assign<base<cpy_ctor> > >);
random_shuffle (RandomAccessIter<assign<base<cpy_ctor> > >,
RandomAccessIter<assign<base<cpy_ctor> > >,
func<const std::size_t >&);
} // namespace std
// 25.2.11, p3 requires that a RandomNumberGenerator take
// and return a value convertible from and to, respectively,
// iterator::difference_type
template <class DifferenceType>
struct Convertible
Convertible (DifferenceType val): val_ (val) { }
operator DifferenceType () /* non-const */ { return val_; }
const DifferenceType val_;
template <class T>
Convertible (T);
// detect assumptions made by the algorithm about the return value
// from RandomGenerator::operator() being anything but convertible
// to the iterator's difference type
template <class DifferenceType, class T>
void operator+ (Convertible<DifferenceType>, T);
template <class DifferenceType, class T>
void operator+ (T, Convertible<DifferenceType>);
template <class DifferenceType>
struct RandomGenerator
// dummy arguments to prevent the class from being default
// constructible or construtible by conversion from an int
RandomGenerator (int, int) {
ncalls_ = 0;
// non-const in order to detect unwarranted assumptions
// in the algorithm(s)
operator() (DifferenceType n) /* non-const */ {
gen_ = (gen_ << 7) + gen_ % 128;
// prevent the number from going negative(!)
if (gen_ < 0)
gen_ = -gen_;
return gen_ % n;
static std::size_t ncalls_;
template <class T>
void operator() (T) /* non-const */;
static DifferenceType gen_;
template <class DifferenceType>
std::size_t RandomGenerator<DifferenceType>::ncalls_ = 0;
template <class DifferenceType>
DifferenceType RandomGenerator<DifferenceType>::gen_ = 12345;
int sequence_start;
int sequence_generator ()
return sequence_start++;
// exercises 25.2.11 -- std::random_shuffle()
template <class T, class Iterator, class RandomNumberGenerator>
void test_random_shuffle (const std::size_t line,
const std::size_t N,
const Iterator &it,
const RandomNumberGenerator*,
const T*,
bool rnd_gen)
const char* const itname = type_name (it, (T*)0);
const char* const fname = "random_shuffle";
const char* const funname = rnd_gen ? "random_generator" : "";
rw_info (0, 0, 0,
"std::%s (%s, %2$s%{?}, %s%{;})",
fname, itname, rnd_gen, funname);
// generate a sequential value for each default-constructed T
// starting with 0 (i.e., T::val_ will be 0 for the first T)
sequence_start = 0;
T::gen_ = sequence_generator;
T *buf = new T [N + 1];
char *missing = new char [N + 1];
for (std::size_t i = 0; i < N; ++i) {
// create a pair of safe iterator to pass to random_shuffle
// in order to test that the function doesn't write past
// the end of the sequence [first, last)
const Iterator first = make_iter (buf, buf, buf + i, it);
const Iterator last = make_iter (buf + i, buf, buf + i, it);
/* non-const */ RandomNumberGenerator rnd (0, 0); // dummy args
// exercise 25.2.11 - std::random_shuffle<>()
std::size_t n_op_assign = T::n_total_op_assign_;
// shuffle buffer elements
if (rnd_gen)
std::random_shuffle (first, last, rnd);
std::random_shuffle (first, last);
n_op_assign = T::n_total_op_assign_ - n_op_assign;
// verify 25.2.11, p1
// iterate over elements of the missing array clearing those
// at the index given by T::val_ to true to verify that the
// algorithm didn't drop any elements
std::size_t j;
std::memset (missing, 1, N);
for (j = 0; j != i; ++j) {
const std::size_t inx = std::size_t (buf [j].data_.val_);
if (inx < N)
missing [inx] = 0;
// find the first missing element (if any)
const char* const first_missing = (char*)std::memchr (missing, 1, i);
bool success = 0 == first_missing;
rw_assert (success, 0, line,
"%zu. std::%s<%s%{?}, %s%{;}>(): can't find element "
"with value %td: got \"%{X=*.*}\"",
i, fname, itname, rnd_gen, funname,
first_missing - missing,
int (i), -1, buf);
// verify 25.2.11, p2, complexity:
// exactly K = ((last - first) - 1) swaps
// i.e., K * 2 assignments (at 2 assignment per swap
// plus one copy construction)
success = n_op_assign == 2 * (i ? i - 1 : i);
rw_assert (success, 0, line,
"%zu. std::%s<%s%{?}, %s%{;}>(): complexity: "
"expected %zu swaps, got %zu",
i, fname, itname, rnd_gen, funname,
2 * i, n_op_assign);
delete[] buf;
delete[] missing;
void test_random_shuffle (const std::size_t line)
rw_info (0, 0, 0,
"verify that the randomly shuffled sequence "
"matches the expected result, this "
"depends on the implementation of the random "
"number generator used by random_shuffle()");
int array[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
std::random_shuffle (array, array + sizeof array / sizeof *array);
const int result[] = {
0xdc, 0x98, 0x6c, 0xcc, 0x1c, 0xb1, 0x2f, 0x13,
0xa4, 0x8b, 0x96, 0x87, 0x95, 0xd8, 0x5e, 0xd5,
0xb6, 0xee, 0xc3, 0x07, 0x68, 0xe4, 0x4e, 0xc0,
0xb7, 0x40, 0x15, 0x55, 0x31, 0x5f, 0xaf, 0xce,
0x01, 0x51, 0x09, 0x4f, 0x0b, 0x80, 0x28, 0x0f,
0xec, 0x43, 0x8a, 0x14, 0x90, 0x9a, 0x7b, 0x3e,
0x81, 0x1e, 0xab, 0xff, 0xed, 0xf6, 0xca, 0x0c,
0x6a, 0x9c, 0x91, 0x60, 0x27, 0xb2, 0x04, 0xd3,
0x72, 0xd7, 0x08, 0x8c, 0x8e, 0x1b, 0x35, 0x49,
0xba, 0x7a, 0xfd, 0x53, 0x22, 0xaa, 0xf5, 0x93,
0xf2, 0x63, 0x05, 0xb4, 0x33, 0x9b, 0xea, 0xc8,
0xc5, 0x39, 0xfc, 0x5d, 0x56, 0x50, 0xe2, 0xf4,
0xc1, 0xa9, 0x76, 0x99, 0xe7, 0xd0, 0xc6, 0x83,
0x11, 0x77, 0x70, 0xa6, 0x46, 0x38, 0x1d, 0x74,
0x6b, 0xdf, 0x30, 0xcf, 0xd1, 0x29, 0x7f, 0x4b,
0xe8, 0x1f, 0xc4, 0xa1, 0x75, 0xae, 0x3f, 0xf1,
0xad, 0x42, 0x2d, 0xfe, 0x62, 0x61, 0x6d, 0x3d,
0xa7, 0x0a, 0x6e, 0xde, 0x16, 0x36, 0xd2, 0xcb,
0x5c, 0xc2, 0x7c, 0xd6, 0x37, 0xa0, 0x20, 0xb5,
0xf3, 0xac, 0x71, 0x64, 0x26, 0x66, 0x88, 0x23,
0x52, 0xdb, 0x2e, 0x10, 0x84, 0x0e, 0x6f, 0x89,
0xb3, 0x86, 0xe5, 0xe6, 0x25, 0x78, 0xd4, 0x2a,
0xa8, 0x5b, 0xc9, 0x44, 0x24, 0x17, 0x1a, 0xf0,
0x69, 0x7e, 0xbf, 0x8d, 0x5a, 0x82, 0x9e, 0xf9,
0xc7, 0xf7, 0x4c, 0x92, 0x9d, 0x34, 0x02, 0x45,
0x59, 0xe1, 0x48, 0x7d, 0xb9, 0x94, 0x41, 0x47,
0x54, 0x00, 0x3c, 0x65, 0xf8, 0xb8, 0xcd, 0x0d,
0xe9, 0x9f, 0x8f, 0x79, 0x3a, 0xda, 0x4a, 0x97,
0xef, 0xa2, 0x21, 0x58, 0x67, 0x32, 0xb0, 0x3b,
0xe0, 0x85, 0x19, 0x12, 0x2c, 0xbc, 0x4d, 0xe3,
0x2b, 0x03, 0xbe, 0xfb, 0xbd, 0x57, 0xeb, 0x06,
0xfa, 0xbb, 0xdd, 0xa5, 0xa3, 0x73, 0x18, 0xd9
bool success = true;
std::size_t i = 0;
for (; i != sizeof array / sizeof *array; ++i) {
success = array [i] == result [i];
if (!success)
rw_assert (success, 0, line,
"randomly shuffled sequence failed to match "
"the expected result (data portability failure) "
"%d != %d at %zu",
array [i], result [i], i + 1);
rw_note (0, 0, 0,
"no random_test available");
/* extern */ int rw_opt_nloops = 1024; // --nloops=#
/* extern */ int rw_opt_no_random; // --no-random
/* extern */ int rw_opt_no_random_generator; // --no-random_generator
/* extern */ int rw_opt_no_rand_test; // --no-rand_test
static int run_test (int, char*[])
const std::size_t N = std::size_t (rw_opt_nloops);
typedef RandomAccessIter<UserClass>::difference_type DiffT;
typedef RandomGenerator<DiffT> RandGenT;
if (rw_opt_no_random) {
rw_note (0, __FILE__, __LINE__, "std::random test disabled");
else {
rw_info (0, 0, 0,
"template <class %s> "
"std::random_shuffle (%1$s, %1$s)",
test_random_shuffle (__LINE__, N, RandomAccessIter<UserClass>(),
(RandGenT*)0, (UserClass*)0, false);
if (rw_opt_no_rand_test) {
rw_note (0, __FILE__, __LINE__, "random algorithm test disabled");
else {
test_random_shuffle (__LINE__);
if (rw_opt_no_random_generator) {
rw_note (0, __FILE__, __LINE__,
"std::random with random_generator test disabled");
else {
rw_info (0, 0, 0,
"template <class %s, class %s> "
"std::random_shuffle (%1$s, %1$s, %2$s)",
"RandomAccessIterator", "RandomNumberGenerator");
test_random_shuffle (__LINE__, N, RandomAccessIter<UserClass>(),
(RandGenT*)0, (UserClass*)0, true);
return 0;
int main (int argc, char *argv[])
return rw_test (argc, argv, __FILE__,
0 /* no comment */, run_test,
"|-nloops#0 " // must be non-negative
"|-no-random# "
"|-no-random_generator# "