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// -- control_structures.cpp -- The Boost Lambda Library ------------------
//
// Copyright (C) 2000-2003 Jaakko Jrvi (jaakko.jarvi@cs.utu.fi)
// Copyright (C) 2000-2003 Gary Powell (powellg@amazon.com)
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see www.boost.org
// -----------------------------------------------------------------------
#include <boost/test/minimal.hpp> // see "Header Implementation Option"
#include "boost/lambda/lambda.hpp"
#include "boost/lambda/if.hpp"
#include "boost/lambda/loops.hpp"
#include <iostream>
#include <algorithm>
#include <vector>
using namespace boost;
using boost::lambda::constant;
using boost::lambda::_1;
using boost::lambda::_2;
using boost::lambda::_3;
using boost::lambda::make_const;
using boost::lambda::for_loop;
using boost::lambda::while_loop;
using boost::lambda::do_while_loop;
using boost::lambda::if_then;
using boost::lambda::if_then_else;
using boost::lambda::if_then_else_return;
// 2 container for_each
template <class InputIter1, class InputIter2, class Function>
Function for_each(InputIter1 first, InputIter1 last,
InputIter2 first2, Function f) {
for ( ; first != last; ++first, ++first2)
f(*first, *first2);
return f;
}
void simple_loops() {
// for loops ---------------------------------------------------------
int i;
int arithmetic_series = 0;
for_loop(_1 = 0, _1 < 10, _1++, arithmetic_series += _1)(i);
BOOST_CHECK(arithmetic_series == 45);
// no body case
for_loop(boost::lambda::var(i) = 0, boost::lambda::var(i) < 100, ++boost::lambda::var(i))();
BOOST_CHECK(i == 100);
// while loops -------------------------------------------------------
int a = 0, b = 0, c = 0;
while_loop((_1 + _2) >= (_1 * _2), (++_1, ++_2, ++_3))(a, b, c);
BOOST_CHECK(c == 3);
int count;
count = 0; i = 0;
while_loop(_1++ < 10, ++boost::lambda::var(count))(i);
BOOST_CHECK(count == 10);
// note that the first parameter of do_while_loop is the condition
count = 0; i = 0;
do_while_loop(_1++ < 10, ++boost::lambda::var(count))(i);
BOOST_CHECK(count == 11);
a = 0;
do_while_loop(constant(false), _1++)(a);
BOOST_CHECK(a == 1);
// no body cases
a = 40; b = 30;
while_loop(--_1 > _2)(a, b);
BOOST_CHECK(a == b);
// (the no body case for do_while_loop is pretty redundant)
a = 40; b = 30;
do_while_loop(--_1 > _2)(a, b);
BOOST_CHECK(a == b);
}
void simple_ifs () {
int value = 42;
if_then(_1 < 0, _1 = 0)(value);
BOOST_CHECK(value == 42);
value = -42;
if_then(_1 < 0, _1 = -_1)(value);
BOOST_CHECK(value == 42);
int min;
if_then_else(_1 < _2, boost::lambda::var(min) = _1, boost::lambda::var(min) = _2)
(make_const(1), make_const(2));
BOOST_CHECK(min == 1);
if_then_else(_1 < _2, boost::lambda::var(min) = _1, boost::lambda::var(min) = _2)
(make_const(5), make_const(3));
BOOST_CHECK(min == 3);
int x, y;
x = -1; y = 1;
BOOST_CHECK(if_then_else_return(_1 < _2, _2, _1)(x, y) == (std::max)(x ,y));
BOOST_CHECK(if_then_else_return(_1 < _2, _2, _1)(y, x) == (std::max)(x ,y));
}
int test_main(int, char *[])
{
simple_loops();
simple_ifs();
return 0;
}
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