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Fixes #5417. Fixes #4397

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More tests (for conversions to float types, for conversions of negative values to unsigned integers)

[SVN r71958]
This commit is contained in:
Antony Polukhin
2011-05-15 15:31:01 +00:00
parent 266ebbcb88
commit 95360b5df6
3 changed files with 356 additions and 14 deletions
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282
include/boost/lexical_cast.hpp
View File

@ -11,8 +11,8 @@
// enhanced with contributions from Terje Slettebo,
// with additional fixes and suggestions from Gennaro Prota,
// Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
// Alexander Nasonov and other Boosters
// when: November 2000, March 2003, June 2005, June 2006
// Alexander Nasonov, Antony Polukhin and other Boosters
// when: November 2000, March 2003, June 2005, June 2006, March 2011
#include <climits>
#include <cstddef>
@ -20,12 +20,18 @@
#include <string>
#include <typeinfo>
#include <exception>
#include <cmath>
#include <boost/config.hpp>
#include <boost/limits.hpp>
#include <boost/mpl/if.hpp>
#include <boost/throw_exception.hpp>
#include <boost/type_traits/is_pointer.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/is_arithmetic.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <boost/type_traits/ice.hpp>
#include <boost/type_traits/make_unsigned.hpp>
#include <boost/type_traits/is_signed.hpp>
#include <boost/call_traits.hpp>
#include <boost/static_assert.hpp>
#include <boost/detail/lcast_precision.hpp>
@ -1161,23 +1167,272 @@ namespace boost
#if (defined _MSC_VER)
# pragma warning( pop )
#endif
template<typename T>
struct is_stdstring
{
BOOST_STATIC_CONSTANT(bool, value = false );
};
template<typename CharT, typename Traits, typename Alloc>
struct is_stdstring< std::basic_string<CharT, Traits, Alloc> >
{
BOOST_STATIC_CONSTANT(bool, value = true );
};
template<typename T>
struct is_char_or_wchar
{
#ifndef BOOST_LCAST_NO_WCHAR_T
BOOST_STATIC_CONSTANT(bool, value =
(
::boost::type_traits::ice_or<
is_same< T, char >::value,
is_same< T, wchar_t >::value,
is_same< T, unsigned char >::value,
is_same< T, signed char >::value
>::value
)
);
#else
BOOST_STATIC_CONSTANT(bool, value =
(
::boost::type_traits::ice_or<
is_same< T, char >::value,
is_same< T, unsigned char >::value,
is_same< T, signed char >::value
>::value
)
);
#endif
};
template<typename Target, typename Source>
struct is_arithmetic_and_not_xchars
{
BOOST_STATIC_CONSTANT(bool, value =
(
::boost::type_traits::ice_and<
is_arithmetic<Source>::value,
is_arithmetic<Target>::value,
::boost::type_traits::ice_not<
detail::is_char_or_wchar<Target>::value
>::value,
::boost::type_traits::ice_not<
detail::is_char_or_wchar<Source>::value
>::value
>::value
)
);
};
template<typename Target, typename Source>
struct is_xchar_to_xchar
{
BOOST_STATIC_CONSTANT(bool, value =
(
::boost::type_traits::ice_and<
is_same<Source,Target>::value,
is_char_or_wchar<Target>::value
>::value
)
);
};
template<typename Target, typename Source>
struct is_char_array_to_stdstring
{
BOOST_STATIC_CONSTANT(bool, value = false );
};
template<typename CharT, typename Traits, typename Alloc>
struct is_char_array_to_stdstring< std::basic_string<CharT, Traits, Alloc>, CharT* >
{
BOOST_STATIC_CONSTANT(bool, value = true );
};
template<typename CharT, typename Traits, typename Alloc>
struct is_char_array_to_stdstring< std::basic_string<CharT, Traits, Alloc>, const CharT* >
{
BOOST_STATIC_CONSTANT(bool, value = true );
};
template<typename Target, typename Source>
struct lexical_cast_do_cast
{
static inline Target lexical_cast_impl(const Source &arg)
{
typedef typename detail::array_to_pointer_decay<Source>::type src;
typedef typename detail::widest_char<
typename detail::stream_char<Target>::type
, typename detail::stream_char<src>::type
>::type char_type;
typedef detail::lcast_src_length<char_type, src> lcast_src_length;
std::size_t const src_len = lcast_src_length::value;
char_type buf[src_len + 1];
lcast_src_length::check_coverage();
return detail::lexical_cast<Target, src, !src_len>(arg, buf, src_len);
}
};
template<typename Source>
struct lexical_cast_copy
{
static inline Source lexical_cast_impl(const Source &arg)
{
return arg;
}
};
class precision_loss_error : public boost::numeric::bad_numeric_cast
{
public:
virtual const char * what() const throw()
{ return "bad numeric conversion: precision loss error"; }
};
template<class S >
struct throw_on_precision_loss
{
typedef boost::numeric::Trunc<S> Rounder;
typedef S source_type ;
typedef typename mpl::if_< is_arithmetic<S>,S,S const&>::type argument_type ;
static source_type nearbyint ( argument_type s )
{
source_type orig_div_round = s / Rounder::nearbyint(s);
if ( (orig_div_round > 1 ? orig_div_round - 1 : 1 - orig_div_round) > std::numeric_limits<source_type>::epsilon() )
BOOST_THROW_EXCEPTION( precision_loss_error() );
return s ;
}
typedef typename Rounder::round_style round_style;
} ;
template<typename Target, typename Source>
struct lexical_cast_dynamic_num_not_ignoring_minus
{
static inline Target lexical_cast_impl(const Source &arg)
{
try{
typedef boost::numeric::converter<
Target,
Source,
boost::numeric::conversion_traits<Target,Source>,
boost::numeric::def_overflow_handler,
throw_on_precision_loss<Source>
> Converter ;
return Converter::convert(arg);
} catch(...) {
BOOST_LCAST_THROW_BAD_CAST(Source, Target);
}
}
};
template<typename Target, typename Source>
struct lexical_cast_dynamic_num_ignoring_minus
{
static inline Target lexical_cast_impl(const Source &arg)
{
try{
typedef boost::numeric::converter<
Target,
Source,
boost::numeric::conversion_traits<Target,Source>,
boost::numeric::def_overflow_handler,
throw_on_precision_loss<Source>
> Converter ;
bool has_minus = ( arg < 0);
if ( has_minus ) {
return static_cast<Target>(-Converter::convert(-arg));
} else {
return Converter::convert(arg);
}
} catch(...) {
BOOST_LCAST_THROW_BAD_CAST(Source, Target);
}
}
};
/*
* lexical_cast_dynamic_num follows the rules:
* 1) If Source can be converted to Target without precision loss and
* without overflows, then assign Source to Target and return
*
* 2) If Source is less than 0 and Target is an unsigned integer,
* then negate Source, check the requirements of rule 1) and if
* successful, assign static_casted Source to Target and return
*
* 3) Otherwise throw a bad_lexical_cast exception
*
*
* Rule 2) required because boost::lexical_cast has the behavior of
* stringstream, which uses the rules of scanf for conversions. And
* in the C99 standard for unsigned input value minus sign is
* optional, so if a negative number is read, no errors will arise
* and the result will be the two's complement.
*/
template<typename Target, typename Source>
struct lexical_cast_dynamic_num
{
static inline Target lexical_cast_impl(const Source &arg)
{
typedef BOOST_DEDUCED_TYPENAME ::boost::mpl::if_c<
::boost::type_traits::ice_and<
::boost::type_traits::ice_or<
::boost::is_signed<Source>::value,
::boost::is_float<Source>::value
>::value,
::boost::type_traits::ice_not<
is_same<Source, bool>::value
>::value,
::boost::type_traits::ice_not<
is_same<Target, bool>::value
>::value,
::boost::is_unsigned<Target>::value
>::value,
lexical_cast_dynamic_num_ignoring_minus<Target, Source>,
lexical_cast_dynamic_num_not_ignoring_minus<Target, Source>
>::type caster_type;
return caster_type::lexical_cast_impl(arg);
}
};
}
template<typename Target, typename Source>
inline Target lexical_cast(const Source &arg)
{
typedef typename detail::array_to_pointer_decay<Source>::type src;
typedef BOOST_DEDUCED_TYPENAME detail::array_to_pointer_decay<Source>::type src;
typedef typename detail::widest_char<
typename detail::stream_char<Target>::type
, typename detail::stream_char<src>::type
>::type char_type;
typedef BOOST_DEDUCED_TYPENAME ::boost::type_traits::ice_or<
detail::is_xchar_to_xchar<Target, src>::value,
detail::is_char_array_to_stdstring<Target,src>::value,
::boost::type_traits::ice_and<
is_same<Target, src>::value,
detail::is_stdstring<Target>::value
>::value
> do_copy_type;
typedef detail::lcast_src_length<char_type, src> lcast_src_length;
std::size_t const src_len = lcast_src_length::value;
char_type buf[src_len + 1];
lcast_src_length::check_coverage();
return detail::lexical_cast<Target, src, !src_len>(arg, buf, src_len);
typedef BOOST_DEDUCED_TYPENAME detail::is_arithmetic_and_not_xchars<Target, src> do_copy_with_dynamic_check_type;
typedef BOOST_DEDUCED_TYPENAME ::boost::mpl::if_c<
do_copy_type::value,
detail::lexical_cast_copy<src>,
BOOST_DEDUCED_TYPENAME ::boost::mpl::if_c<
do_copy_with_dynamic_check_type::value,
detail::lexical_cast_dynamic_num<Target, src>,
detail::lexical_cast_do_cast<Target, src>
>::type
>::type caster_type;
return caster_type::lexical_cast_impl(arg);
}
#else
@ -1205,7 +1460,8 @@ namespace boost
}
// Copyright Kevlin Henney, 2000-2005.
// Copyright Alexander Nasonov, 2006-2007.
// Copyright Alexander Nasonov, 2006-2010.
// Copyright Antony Polukhin, 2011.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at

5
lexical_cast.htm
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@ -265,6 +265,11 @@ Eliminate an overhead of <code>std::locale</code> if your program runs in the "C
August 2006.</li>
</ul>
<h2><a name="changes">Changes</a></h2>
<h3>May 2011:</h3>
<ul type="square">
<li>Better performance for conversions from arithmetic type to arithmetic type.</li>
<li>Directly construct <code>Target</code> from <code>Source</code> on some conversions (like conversions from string to string, from char array to string, from char to char and others).</li>
</ul>
<h3>August, October 2006:</h3>
<ul type="square">
<li>Better performance for many combinations of <code>Source</code> and <code>Target</code>

83
lexical_cast_test.cpp
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@ -2,7 +2,7 @@
//
// See http://www.boost.org for most recent version, including documentation.
//
// Copyright Terje Sletteb<EFBFBD> and Kevlin Henney, 2005.
// Copyright Terje Sletteb and Kevlin Henney, 2005.
// Copyright Alexander Nasonov, 2006.
//
// Distributed under the Boost
@ -84,6 +84,9 @@ void test_conversion_from_to_uintmax_t();
void test_conversion_from_to_longlong();
void test_conversion_from_to_ulonglong();
#endif
void test_conversion_from_to_float();
void test_conversion_from_to_double();
void test_conversion_from_to_long_double();
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
void test_traits();
void test_wtraits();
@ -122,6 +125,9 @@ unit_test::test_suite *init_unit_test_suite(int, char *[])
suite->add(BOOST_TEST_CASE(&test_conversion_from_to_longlong));
suite->add(BOOST_TEST_CASE(&test_conversion_from_to_ulonglong));
#endif
suite->add(BOOST_TEST_CASE(&test_conversion_from_to_float));
suite->add(BOOST_TEST_CASE(&test_conversion_from_to_double));
suite->add(BOOST_TEST_CASE(&test_conversion_from_to_long_double));
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
suite->add(BOOST_TEST_CASE(&test_traits));
suite->add(BOOST_TEST_CASE(&test_wtraits));
@ -447,6 +453,24 @@ void test_conversion_from_integral_to_char(CharT zero)
BOOST_CHECK_THROW(lexical_cast<CharT>(t), bad_lexical_cast);
}
template<class T, class CharT>
void test_conversion_from_char_to_integral(CharT zero)
{
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 0)) == static_cast<T>(0) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 1)) == static_cast<T>(1) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 2)) == static_cast<T>(2) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 3)) == static_cast<T>(3) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 4)) == static_cast<T>(4) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 5)) == static_cast<T>(5) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 6)) == static_cast<T>(6) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 7)) == static_cast<T>(7) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 8)) == static_cast<T>(8) );
BOOST_CHECK(lexical_cast<T>( static_cast<CharT>(zero + 9)) == static_cast<T>(9) );
BOOST_CHECK_THROW(lexical_cast<T>( static_cast<CharT>(zero + 10)), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>( static_cast<CharT>(zero - 1)), bad_lexical_cast);
}
template<class T>
void test_conversion_from_integral_to_integral()
{
@ -625,13 +649,36 @@ void test_conversion_from_to_integral()
signed char const szero = '0';
unsigned char const uzero = '0';
test_conversion_from_integral_to_char<T>(zero);
test_conversion_from_char_to_integral<T>(zero);
test_conversion_from_integral_to_char<T>(szero);
test_conversion_from_char_to_integral<T>(szero);
test_conversion_from_integral_to_char<T>(uzero);
test_conversion_from_char_to_integral<T>(uzero);
#if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
wchar_t const wzero = L'0';
test_conversion_from_integral_to_char<T>(wzero);
test_conversion_from_char_to_integral<T>(wzero);
#endif
BOOST_CHECK(lexical_cast<T>("-1") == static_cast<T>(-1));
BOOST_CHECK(lexical_cast<T>("-9") == static_cast<T>(-9));
BOOST_CHECK(lexical_cast<T>(-1) == static_cast<T>(-1));
BOOST_CHECK(lexical_cast<T>(-9) == static_cast<T>(-9));
BOOST_CHECK_THROW(lexical_cast<T>("-1.0"), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>("-9.0"), bad_lexical_cast);
BOOST_CHECK(lexical_cast<T>(-1.0) == static_cast<T>(-1));
BOOST_CHECK(lexical_cast<T>(-9.0) == static_cast<T>(-9));
BOOST_CHECK(lexical_cast<T>(static_cast<T>(1)) == static_cast<T>(1));
BOOST_CHECK(lexical_cast<T>(static_cast<T>(9)) == static_cast<T>(9));
BOOST_CHECK_THROW(lexical_cast<T>(1.1f), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>(1.1), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>(1.1L), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>(1.0001f), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>(1.0001), bad_lexical_cast);
BOOST_CHECK_THROW(lexical_cast<T>(1.0001L), bad_lexical_cast);
// test_conversion_from_to_integral_for_locale
typedef std::numpunct<char> numpunct;
@ -665,6 +712,27 @@ void test_conversion_from_to_integral()
BOOST_TEST_MESSAGE("Formatting with thousands_sep has not been tested");
}
template<class T>
void test_conversion_from_to_float()
{
char const zero = '0';
signed char const szero = '0';
unsigned char const uzero = '0';
test_conversion_from_integral_to_char<T>(zero);
test_conversion_from_char_to_integral<T>(zero);
test_conversion_from_integral_to_char<T>(szero);
test_conversion_from_char_to_integral<T>(szero);
test_conversion_from_integral_to_char<T>(uzero);
test_conversion_from_char_to_integral<T>(uzero);
#if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
wchar_t const wzero = L'0';
test_conversion_from_integral_to_char<T>(wzero);
test_conversion_from_char_to_integral<T>(wzero);
#endif
test_conversion_from_integral_to_integral<T>();
}
void test_conversion_from_to_short()
{
test_conversion_from_to_integral<short>();
@ -717,6 +785,19 @@ void test_conversion_from_to_ulonglong()
test_conversion_from_to_integral<boost::ulong_long_type>();
}
void test_conversion_from_to_float()
{
test_conversion_from_to_float<float>();
}
void test_conversion_from_to_double()
{
test_conversion_from_to_float<double>();
}
void test_conversion_from_to_long_double()
{
test_conversion_from_to_float<long double>();
}
#elif defined(LCAST_TEST_LONGLONG)
void test_conversion_from_to_longlong()