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366 lines (300 loc) · 10.2 KB
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// Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal.
// Copyright (C) 2015 Andrzej Krzemienski.
//
// Use, modification, and distribution is subject to 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)
//
// See http://www.boost.org/lib/optional for documentation.
//
// You are welcome to contact the author at:
// fernando_cacciola@hotmail.com
//
// Revisions:
// 12 May 2008 (added more swap tests)
//
#include "boost/optional/optional.hpp"
#include "boost/utility/in_place_factory.hpp"
#ifdef BOOST_BORLANDC
#pragma hdrstop
#endif
#include "boost/core/lightweight_test.hpp"
#if __cplusplus < 201103L
#include <algorithm>
#else
#include <utility>
#endif
using boost::optional;
using boost::none;
#define ARG(T) (static_cast< T const* >(0))
namespace optional_swap_test
{
class default_ctor_exception : public std::exception {} ;
class copy_ctor_exception : public std::exception {} ;
class assignment_exception : public std::exception {} ;
//
// Base class for swap test classes. Its assignment should not be called, when swapping
// optional<T> objects. (The default std::swap would do so.)
//
class base_class_with_forbidden_assignment
{
public:
base_class_with_forbidden_assignment & operator=(const base_class_with_forbidden_assignment &)
{
BOOST_TEST(!"The assignment should not be used while swapping!");
throw assignment_exception();
}
virtual ~base_class_with_forbidden_assignment() {}
};
//
// Class without default constructor
//
class class_without_default_ctor : public base_class_with_forbidden_assignment
{
public:
char data;
explicit class_without_default_ctor(char arg) : data(arg) {}
};
//
// Class whose default constructor should not be used by optional::swap!
//
class class_whose_default_ctor_should_not_be_used : public base_class_with_forbidden_assignment
{
public:
char data;
explicit class_whose_default_ctor_should_not_be_used(char arg) : data(arg) {}
class_whose_default_ctor_should_not_be_used()
{
BOOST_TEST(!"This default constructor should not be used while swapping!");
throw default_ctor_exception();
}
};
//
// Class whose default constructor should be used by optional::swap.
// Its copy constructor should be avoided!
//
class class_whose_default_ctor_should_be_used : public base_class_with_forbidden_assignment
{
public:
char data;
explicit class_whose_default_ctor_should_be_used(char arg) : data(arg) { }
class_whose_default_ctor_should_be_used() : data('\0') { }
class_whose_default_ctor_should_be_used(const class_whose_default_ctor_should_be_used &)
{
BOOST_TEST(!"This copy constructor should not be used while swapping!");
throw copy_ctor_exception();
}
};
//
// Class template whose default constructor should be used by optional::swap.
// Its copy constructor should be avoided!
//
template <class T>
class template_whose_default_ctor_should_be_used : public base_class_with_forbidden_assignment
{
public:
T data;
explicit template_whose_default_ctor_should_be_used(T arg) : data(arg) { }
template_whose_default_ctor_should_be_used() : data('\0') { }
template_whose_default_ctor_should_be_used(const template_whose_default_ctor_should_be_used &)
{
BOOST_TEST(!"This copy constructor should not be used while swapping!");
throw copy_ctor_exception();
}
};
//
// Class whose explicit constructor should be used by optional::swap.
// Its other constructors should be avoided!
//
class class_whose_explicit_ctor_should_be_used : public base_class_with_forbidden_assignment
{
public:
char data;
explicit class_whose_explicit_ctor_should_be_used(char arg) : data(arg) { }
class_whose_explicit_ctor_should_be_used()
{
BOOST_TEST(!"This default constructor should not be used while swapping!");
throw default_ctor_exception();
}
class_whose_explicit_ctor_should_be_used(const class_whose_explicit_ctor_should_be_used &)
{
BOOST_TEST(!"This copy constructor should not be used while swapping!");
throw copy_ctor_exception();
}
};
void swap(class_whose_default_ctor_should_not_be_used & lhs, class_whose_default_ctor_should_not_be_used & rhs)
{
std::swap(lhs.data, rhs.data);
}
void swap(class_whose_default_ctor_should_be_used & lhs, class_whose_default_ctor_should_be_used & rhs)
{
std::swap(lhs.data, rhs.data);
}
void swap(class_without_default_ctor & lhs, class_without_default_ctor & rhs)
{
std::swap(lhs.data, rhs.data);
}
void swap(class_whose_explicit_ctor_should_be_used & lhs, class_whose_explicit_ctor_should_be_used & rhs)
{
std::swap(lhs.data, rhs.data);
}
template <class T>
void swap(template_whose_default_ctor_should_be_used<T> & lhs, template_whose_default_ctor_should_be_used<T> & rhs)
{
std::swap(lhs.data, rhs.data);
}
//
// optional<T>::swap should be customized when neither the copy constructor
// nor the default constructor of T are supposed to be used when swapping, e.g.,
// for the following type T = class_whose_explicit_ctor_should_be_used.
//
void swap(boost::optional<class_whose_explicit_ctor_should_be_used> & x, boost::optional<class_whose_explicit_ctor_should_be_used> & y)
{
bool hasX(x);
bool hasY(y);
if ( !hasX && !hasY )
return;
if( !hasX )
x = boost::in_place('\0');
else if ( !hasY )
y = boost::in_place('\0');
optional_swap_test::swap(*x,*y);
if( !hasX )
y = boost::none ;
else if( !hasY )
x = boost::none ;
}
} // End of namespace optional_swap_test.
namespace boost {
//
// Compile time tweaking on whether or not swap should use the default constructor:
//
template <> struct optional_swap_should_use_default_constructor<
optional_swap_test::class_whose_default_ctor_should_be_used> : true_type {} ;
template <> struct optional_swap_should_use_default_constructor<
optional_swap_test::class_whose_default_ctor_should_not_be_used> : false_type {} ;
template <class T> struct optional_swap_should_use_default_constructor<
optional_swap_test::template_whose_default_ctor_should_be_used<T> > : true_type {} ;
//
// Specialization of boost::swap:
//
template <>
void swap(optional<optional_swap_test::class_whose_explicit_ctor_should_be_used> & x, optional<optional_swap_test::class_whose_explicit_ctor_should_be_used> & y)
{
optional_swap_test::swap(x, y);
}
} // namespace boost
namespace std {
//
// Specializations of std::swap:
//
template <>
void swap(optional_swap_test::class_whose_default_ctor_should_be_used & x, optional_swap_test::class_whose_default_ctor_should_be_used & y)
{
optional_swap_test::swap(x, y);
}
template <>
void swap(optional_swap_test::class_whose_default_ctor_should_not_be_used & x, optional_swap_test::class_whose_default_ctor_should_not_be_used & y)
{
optional_swap_test::swap(x, y);
}
template <>
void swap(optional_swap_test::class_without_default_ctor & x, optional_swap_test::class_without_default_ctor & y)
{
optional_swap_test::swap(x, y);
}
template <>
void swap(optional_swap_test::class_whose_explicit_ctor_should_be_used & x, optional_swap_test::class_whose_explicit_ctor_should_be_used & y)
{
optional_swap_test::swap(x, y);
}
} // namespace std
//
// Tests whether the swap function works properly for optional<T>.
// Assumes that T has one data member, of type char.
// Returns true iff the test is passed.
//
template <class T>
void test_swap_function( T const* )
{
try
{
optional<T> obj1;
optional<T> obj2('a');
// Self-swap should not have any effect.
swap(obj1, obj1);
swap(obj2, obj2);
BOOST_TEST(!obj1);
BOOST_TEST(!!obj2 && obj2->data == 'a');
// Call non-member swap.
swap(obj1, obj2);
// Test if obj1 and obj2 are really swapped.
BOOST_TEST(!!obj1 && obj1->data == 'a');
BOOST_TEST(!obj2);
// Call non-member swap one more time.
swap(obj1, obj2);
// Test if obj1 and obj2 are swapped back.
BOOST_TEST(!obj1);
BOOST_TEST(!!obj2 && obj2->data == 'a');
}
catch(const std::exception &)
{
// The swap function should not throw, for our test cases.
BOOST_TEST(!"throw in swap");
}
}
//
// Tests whether the optional<T>::swap member function works properly.
// Assumes that T has one data member, of type char.
// Returns true iff the test is passed.
//
template <class T>
void test_swap_member_function( T const* )
{
try
{
optional<T> obj1;
optional<T> obj2('a');
// Self-swap should not have any effect.
obj1.swap(obj1);
obj2.swap(obj2);
BOOST_TEST(!obj1);
BOOST_TEST(!!obj2 && obj2->data == 'a');
// Call member swap.
obj1.swap(obj2);
// Test if obj1 and obj2 are really swapped.
BOOST_TEST(!!obj1 && obj1->data == 'a');
BOOST_TEST(!obj2);
// Call member swap one more time.
obj1.swap(obj2);
// Test if obj1 and obj2 are swapped back.
BOOST_TEST(!obj1);
BOOST_TEST(!!obj2 && obj2->data == 'a');
}
catch(const std::exception &)
{
BOOST_TEST(!"throw in swap");
}
}
//
// Tests compile time tweaking of swap, by means of
// optional_swap_should_use_default_constructor.
//
void test_swap_tweaking()
{
( test_swap_function( ARG(optional_swap_test::class_without_default_ctor) ) );
( test_swap_function( ARG(optional_swap_test::class_whose_default_ctor_should_be_used) ) );
( test_swap_function( ARG(optional_swap_test::class_whose_default_ctor_should_not_be_used) ) );
( test_swap_function( ARG(optional_swap_test::class_whose_explicit_ctor_should_be_used) ) );
( test_swap_function( ARG(optional_swap_test::template_whose_default_ctor_should_be_used<char>) ) );
( test_swap_member_function( ARG(optional_swap_test::class_without_default_ctor) ) );
( test_swap_member_function( ARG(optional_swap_test::class_whose_default_ctor_should_be_used) ) );
( test_swap_member_function( ARG(optional_swap_test::class_whose_default_ctor_should_not_be_used) ) );
( test_swap_member_function( ARG(optional_swap_test::class_whose_explicit_ctor_should_be_used) ) );
( test_swap_member_function( ARG(optional_swap_test::template_whose_default_ctor_should_be_used<char>) ) );
}
int main()
{
test_swap_tweaking();
return boost::report_errors();
}
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