conversion/lexical_cast_test.cpp

//  Unit test for boost::lexical_cast.
//
//  See http://www.boost.org for most recent version, including documentation.
//
//  Copyright Terje Slettebø and Kevlin Henney, 2005.
//  Copyright Alexander Nasonov, 2006.
//
//  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).
//
// Note: The unit test no longer compile on MSVC 6, but lexical_cast itself works for it.

#include <boost/config.hpp>

#if defined(__INTEL_COMPILER)
#pragma warning(disable: 193 383 488 981 1418 1419)
#elif defined(BOOST_MSVC)
#pragma warning(disable: 4097 4100 4121 4127 4146 4244 4245 4511 4512 4701 4800)
#endif

#include <boost/lexical_cast.hpp>

#include <boost/test/unit_test.hpp>
#include <boost/test/floating_point_comparison.hpp>

#if defined(BOOST_NO_STRINGSTREAM) || \
    defined(BOOST_NO_STD_WSTRING) || \
    defined(BOOST_NO_STD_LOCALE)
#define DISABLE_WIDE_CHAR_SUPPORT
#endif

#if (defined(BOOST_HAS_LONG_LONG) || defined(BOOST_HAS_MS_INT64)) \
    && !(defined(BOOST_MSVC) && BOOST_MSVC < 1300)
#define LCAST_TEST_LONGLONG
#endif

// Test all 65536 values if true:
bool const lcast_test_small_integral_types_completely = false;

// lcast_integral_test_counter: use when testing all values of an integral
// types is not possible. Max. portable value is 32767.
int const lcast_integral_test_counter=1000;

using namespace boost;

void test_conversion_to_char();
void test_conversion_to_int();
void test_conversion_to_double();
void test_conversion_to_bool();
void test_conversion_to_string();
void test_conversion_from_to_wchar_t_alias();
void test_conversion_to_pointer();
void test_conversion_from_wchar_t();
void test_conversion_to_wchar_t();
void test_conversion_from_wstring();
void test_conversion_to_wstring();
void test_bad_lexical_cast();
void test_no_whitespace_stripping();
void test_conversion_from_short();
void test_conversion_from_ushort();
void test_conversion_from_int();
void test_conversion_from_uint();
void test_conversion_from_long();
void test_conversion_from_ulong();
#ifdef LCAST_TEST_LONGLONG
void test_conversion_from_longlong();
void test_conversion_from_ulonglong();
#endif
void test_round_conversion_float();
void test_round_conversion_double();
void test_round_conversion_long_double();

unit_test::test_suite *init_unit_test_suite(int, char *[])
{
    unit_test_framework::test_suite *suite =
        BOOST_TEST_SUITE("lexical_cast unit test");
    suite->add(BOOST_TEST_CASE(test_conversion_to_char));
    suite->add(BOOST_TEST_CASE(test_conversion_to_int));
    suite->add(BOOST_TEST_CASE(test_conversion_to_double));
    suite->add(BOOST_TEST_CASE(test_conversion_to_bool));
    suite->add(BOOST_TEST_CASE(test_conversion_from_to_wchar_t_alias));
    suite->add(BOOST_TEST_CASE(test_conversion_to_pointer));
    suite->add(BOOST_TEST_CASE(test_conversion_to_string));
    #ifndef DISABLE_WIDE_CHAR_SUPPORT
    suite->add(BOOST_TEST_CASE(test_conversion_from_wchar_t));
    suite->add(BOOST_TEST_CASE(test_conversion_to_wchar_t));
    suite->add(BOOST_TEST_CASE(test_conversion_from_wstring));
    suite->add(BOOST_TEST_CASE(test_conversion_to_wstring));
    #endif
    suite->add(BOOST_TEST_CASE(test_bad_lexical_cast));
    suite->add(BOOST_TEST_CASE(test_no_whitespace_stripping));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_short));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_ushort));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_int));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_uint));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_ulong));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_long));
    #ifdef LCAST_TEST_LONGLONG
    suite->add(BOOST_TEST_CASE(&test_conversion_from_longlong));
    suite->add(BOOST_TEST_CASE(&test_conversion_from_ulonglong));
    #endif
    suite->add(BOOST_TEST_CASE(&test_round_conversion_float));
    suite->add(BOOST_TEST_CASE(&test_round_conversion_double));
    suite->add(BOOST_TEST_CASE(&test_round_conversion_long_double));

    return suite;
}

void test_conversion_to_char()
{
    BOOST_CHECK_EQUAL('A', lexical_cast<char>('A'));
    BOOST_CHECK_EQUAL(' ', lexical_cast<char>(' '));
    BOOST_CHECK_EQUAL('1', lexical_cast<char>(1));
    BOOST_CHECK_EQUAL('0', lexical_cast<char>(0));
    BOOST_CHECK_THROW(lexical_cast<char>(123), bad_lexical_cast);
    BOOST_CHECK_EQUAL('1', lexical_cast<char>(1.0));
    BOOST_CHECK_EQUAL('1', lexical_cast<char>(true));
    BOOST_CHECK_EQUAL('0', lexical_cast<char>(false));
    BOOST_CHECK_EQUAL('A', lexical_cast<char>("A"));
    BOOST_CHECK_EQUAL(' ', lexical_cast<char>(" "));
    BOOST_CHECK_THROW(lexical_cast<char>(""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<char>("Test"), bad_lexical_cast);
    BOOST_CHECK_EQUAL('A', lexical_cast<char>(std::string("A")));
    BOOST_CHECK_EQUAL(' ', lexical_cast<char>(std::string(" ")));
    BOOST_CHECK_THROW(
        lexical_cast<char>(std::string("")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<char>(std::string("Test")), bad_lexical_cast);
}

void test_conversion_to_int()
{
    BOOST_CHECK_EQUAL(1, lexical_cast<int>('1'));
    BOOST_CHECK_EQUAL(0, lexical_cast<int>('0'));
    BOOST_CHECK_THROW(lexical_cast<int>('A'), bad_lexical_cast);
    BOOST_CHECK_EQUAL(1, lexical_cast<int>(1));
    BOOST_CHECK_EQUAL(
        (std::numeric_limits<int>::max)(),
        lexical_cast<int>((std::numeric_limits<int>::max)()));
    BOOST_CHECK_EQUAL(1, lexical_cast<int>(1.0));

    BOOST_CHECK_THROW(lexical_cast<int>(1.23), bad_lexical_cast);

    BOOST_CHECK_THROW(lexical_cast<int>(1e20), bad_lexical_cast);
    BOOST_CHECK_EQUAL(1, lexical_cast<int>(true));
    BOOST_CHECK_EQUAL(0, lexical_cast<int>(false));
    BOOST_CHECK_EQUAL(123, lexical_cast<int>("123"));
    BOOST_CHECK_THROW(
        lexical_cast<int>(" 123"), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<int>(""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<int>("Test"), bad_lexical_cast);
    BOOST_CHECK_EQUAL(123, lexical_cast<int>("123"));
    BOOST_CHECK_EQUAL(123, lexical_cast<int>(std::string("123")));
    BOOST_CHECK_THROW(
        lexical_cast<int>(std::string(" 123")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<int>(std::string("")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<int>(std::string("Test")), bad_lexical_cast);
}

void test_conversion_to_double()
{
    BOOST_CHECK_CLOSE(1.0, lexical_cast<double>('1'), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_THROW(lexical_cast<double>('A'), bad_lexical_cast);
    BOOST_CHECK_CLOSE(1.0, lexical_cast<double>(1), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_CLOSE(1.23, lexical_cast<double>(1.23), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_CLOSE(1.234567890, 1.234567890, std::numeric_limits<double>::epsilon());
    BOOST_CHECK_CLOSE(1.0, lexical_cast<double>(true), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_CLOSE(0.0, lexical_cast<double>(false), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_CLOSE(1.23, lexical_cast<double>("1.23"), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_THROW(lexical_cast<double>(""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<double>("Test"), bad_lexical_cast);
    BOOST_CHECK_CLOSE(1.23, lexical_cast<double>(std::string("1.23")), (std::numeric_limits<double>::epsilon()));
    BOOST_CHECK_THROW(
        lexical_cast<double>(std::string("")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<double>(std::string("Test")), bad_lexical_cast);
}

void test_conversion_to_bool()
{
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>('1'));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>('0'));
    BOOST_CHECK_THROW(lexical_cast<bool>('A'), bad_lexical_cast);
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(1));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(0));
    BOOST_CHECK_THROW(lexical_cast<bool>(123), bad_lexical_cast);
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(1.0));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(0.0));
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(true));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(false));
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>("1"));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>("0"));
    BOOST_CHECK_THROW(lexical_cast<bool>(""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<bool>("Test"), bad_lexical_cast);
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>("1"));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>("0"));
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(std::string("1")));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(std::string("0")));
    BOOST_CHECK_THROW(
        lexical_cast<bool>(std::string("")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<bool>(std::string("Test")), bad_lexical_cast);
}

void test_conversion_to_string()
{
    char buf[] = "hello";
    char* str = buf;
    BOOST_CHECK_EQUAL(str, lexical_cast<std::string>(str));
    BOOST_CHECK_EQUAL("A", lexical_cast<std::string>('A'));
    BOOST_CHECK_EQUAL(" ", lexical_cast<std::string>(' '));
    BOOST_CHECK_EQUAL("123", lexical_cast<std::string>(123));
    BOOST_CHECK_EQUAL("1.23", lexical_cast<std::string>(1.23));
    BOOST_CHECK_EQUAL("1.111111111", lexical_cast<std::string>(1.111111111));
    BOOST_CHECK_EQUAL("1", lexical_cast<std::string>(true));
    BOOST_CHECK_EQUAL("0", lexical_cast<std::string>(false));
    BOOST_CHECK_EQUAL("Test", lexical_cast<std::string>("Test"));
    BOOST_CHECK_EQUAL(" ", lexical_cast<std::string>(" "));
    BOOST_CHECK_EQUAL("", lexical_cast<std::string>(""));
    BOOST_CHECK_EQUAL("Test", lexical_cast<std::string>(std::string("Test")));
    BOOST_CHECK_EQUAL(" ", lexical_cast<std::string>(std::string(" ")));
    BOOST_CHECK_EQUAL("", lexical_cast<std::string>(std::string("")));
}

void test_conversion_from_to_wchar_t_alias()
{
    BOOST_CHECK_EQUAL(123u, lexical_cast<unsigned short>("123"));
    BOOST_CHECK_EQUAL(123u, lexical_cast<unsigned int>("123"));
    BOOST_CHECK_EQUAL(123u, lexical_cast<unsigned long>("123"));
    BOOST_CHECK_EQUAL(std::string("123"),
        lexical_cast<std::string>(static_cast<unsigned short>(123)));
    BOOST_CHECK_EQUAL(std::string("123"), lexical_cast<std::string>(123u));
    BOOST_CHECK_EQUAL(std::string("123"), lexical_cast<std::string>(123ul));
}

void test_conversion_to_pointer()
{
    BOOST_CHECK_THROW(lexical_cast<char *>("Test"), bad_lexical_cast);
    #ifndef DISABLE_WIDE_CHAR_SUPPORT
    BOOST_CHECK_THROW(lexical_cast<wchar_t *>("Test"), bad_lexical_cast);
    #endif
}

void test_conversion_from_wchar_t()
{
#ifndef DISABLE_WIDE_CHAR_SUPPORT
#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
    BOOST_CHECK_EQUAL(1, lexical_cast<int>(L'1'));
    BOOST_CHECK_THROW(lexical_cast<int>(L'A'), bad_lexical_cast);
#endif

    BOOST_CHECK_EQUAL(123, lexical_cast<int>(L"123"));
    BOOST_CHECK_THROW(lexical_cast<int>(L""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<int>(L"Test"), bad_lexical_cast);

#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
    BOOST_CHECK_EQUAL(1.0, lexical_cast<double>(L'1'));
    BOOST_CHECK_THROW(lexical_cast<double>(L'A'), bad_lexical_cast);
#endif

    BOOST_CHECK_EQUAL(1.23, lexical_cast<double>(L"1.23"));
    BOOST_CHECK_THROW(lexical_cast<double>(L""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<double>(L"Test"), bad_lexical_cast);

#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(L'1'));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(L'0'));
    BOOST_CHECK_THROW(lexical_cast<bool>(L'A'), bad_lexical_cast);
#endif
    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(L"1"));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(L"0"));
    BOOST_CHECK_THROW(lexical_cast<bool>(L""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<bool>(L"Test"), bad_lexical_cast);
#endif
}

void test_conversion_to_wchar_t()
{
#if !defined(DISABLE_WIDE_CHAR_SUPPORT) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
    BOOST_CHECK_EQUAL(L'1', lexical_cast<wchar_t>(1));
    BOOST_CHECK_EQUAL(L'0', lexical_cast<wchar_t>(0));
    BOOST_CHECK_EQUAL(L'1', lexical_cast<wchar_t>('1'));
    BOOST_CHECK_EQUAL(L'0', lexical_cast<wchar_t>('0'));
    BOOST_CHECK_THROW(lexical_cast<wchar_t>(123), bad_lexical_cast);
    BOOST_CHECK_EQUAL(L'1', lexical_cast<wchar_t>(1.0));
    BOOST_CHECK_EQUAL(L'0', lexical_cast<wchar_t>(0.0));
    BOOST_CHECK_EQUAL(L'1', lexical_cast<wchar_t>(true));
    BOOST_CHECK_EQUAL(L'0', lexical_cast<wchar_t>(false));
    BOOST_CHECK_EQUAL(L'A', lexical_cast<wchar_t>(L'A'));
    BOOST_CHECK_EQUAL(L' ', lexical_cast<wchar_t>(L' '));
    BOOST_CHECK_EQUAL(L'A', lexical_cast<wchar_t>(L"A"));
    BOOST_CHECK_EQUAL(L' ', lexical_cast<wchar_t>(L" "));
    BOOST_CHECK_THROW(lexical_cast<wchar_t>(L""), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<wchar_t>(L"Test"), bad_lexical_cast);
    BOOST_CHECK_EQUAL(L'A', lexical_cast<wchar_t>(std::wstring(L"A")));
    BOOST_CHECK_EQUAL(L' ', lexical_cast<wchar_t>(std::wstring(L" ")));
    BOOST_CHECK_THROW(
        lexical_cast<wchar_t>(std::wstring(L"")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<wchar_t>(std::wstring(L"Test")), bad_lexical_cast);
    #endif
}

void test_conversion_from_wstring()
{
    #ifndef DISABLE_WIDE_CHAR_SUPPORT
    BOOST_CHECK_EQUAL(123, lexical_cast<int>(std::wstring(L"123")));
    BOOST_CHECK_THROW(
        lexical_cast<int>(std::wstring(L"")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<int>(std::wstring(L"Test")), bad_lexical_cast);

    BOOST_CHECK_EQUAL(true, lexical_cast<bool>(std::wstring(L"1")));
    BOOST_CHECK_EQUAL(false, lexical_cast<bool>(std::wstring(L"0")));
    BOOST_CHECK_THROW(
        lexical_cast<bool>(std::wstring(L"")), bad_lexical_cast);
    BOOST_CHECK_THROW(
        lexical_cast<bool>(std::wstring(L"Test")), bad_lexical_cast);
    #endif
}

void test_conversion_to_wstring()
{
    #ifndef DISABLE_WIDE_CHAR_SUPPORT
    wchar_t buf[] = L"hello";
    wchar_t* str = buf;
    BOOST_CHECK(str == lexical_cast<std::wstring>(str));
    BOOST_CHECK(L"123" == lexical_cast<std::wstring>(123));
    BOOST_CHECK(L"1.23" == lexical_cast<std::wstring>(1.23));
    BOOST_CHECK(L"1.111111111" == lexical_cast<std::wstring>(1.111111111));
    BOOST_CHECK(L"1" == lexical_cast<std::wstring>(true));
    BOOST_CHECK(L"0" == lexical_cast<std::wstring>(false));
#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
    BOOST_CHECK(L"A" == lexical_cast<std::wstring>(L'A'));
    BOOST_CHECK(L" " == lexical_cast<std::wstring>(L' '));
    BOOST_CHECK(L"A" == lexical_cast<std::wstring>('A'));
#endif
    BOOST_CHECK(L"Test" == lexical_cast<std::wstring>(L"Test"));
    BOOST_CHECK(L" " == lexical_cast<std::wstring>(L" "));
    BOOST_CHECK(L"" == lexical_cast<std::wstring>(L""));
    BOOST_CHECK(L"Test" == lexical_cast<std::wstring>(std::wstring(L"Test")));
    BOOST_CHECK(L" " == lexical_cast<std::wstring>(std::wstring(L" ")));
    BOOST_CHECK(L"" == lexical_cast<std::wstring>(std::wstring(L"")));
    #endif
}

void test_bad_lexical_cast()
{
    try
    {
        lexical_cast<int>(std::string("Test"));

        BOOST_CHECK(false); // Exception expected
    }
    catch(const bad_lexical_cast &e)
    {
        BOOST_CHECK(e.source_type() == typeid(std::string));
        BOOST_CHECK(e.target_type() == typeid(int));
    }
}

void test_no_whitespace_stripping()
{
    BOOST_CHECK_THROW(lexical_cast<int>(" 123"), bad_lexical_cast);
    BOOST_CHECK_THROW(lexical_cast<int>("123 "), bad_lexical_cast);
}

// Replace "-,999" with "-999".
template<class CharT>
std::basic_string<CharT> to_str_gcc_workaround(std::basic_string<CharT> str)
{
    std::locale loc;
    std::numpunct<CharT> const& np = BOOST_USE_FACET(std::numpunct<CharT>, loc);
    std::ctype<CharT> const& ct = BOOST_USE_FACET(std::ctype<CharT>, loc);

    if(np.grouping().empty())
        return str;

    CharT prefix[3] = { ct.widen('-'), np.thousands_sep(), CharT() };

    if(str.find(prefix) != 0)
        return str;

    prefix[1] = CharT();
    str.replace(0, 2, prefix);
    return str;
}

template<class CharT, class T>
std::basic_string<CharT> to_str(T t)
{
    std::basic_ostringstream<CharT> o;
    o << t;
    return to_str_gcc_workaround(o.str());
}

template<class T, class CharT>
void test_conversion_from_integral_to_char(CharT zero)
{
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(0)) == zero + 0);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(1)) == zero + 1);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(2)) == zero + 2);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(3)) == zero + 3);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(4)) == zero + 4);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(5)) == zero + 5);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(6)) == zero + 6);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(7)) == zero + 7);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(8)) == zero + 8);
    BOOST_CHECK(lexical_cast<CharT>(static_cast<T>(9)) == zero + 9);

    BOOST_CHECK_THROW(lexical_cast<CharT>(static_cast<T>(10)), bad_lexical_cast);

    T t = std::numeric_limits<T>::max();
    BOOST_CHECK_THROW(lexical_cast<CharT>(t), bad_lexical_cast);
}

template<class T>
void test_conversion_from_integral_to_integral()
{
    T t = 0;
    BOOST_CHECK(lexical_cast<T>(t) == t);

    // Next two variables are used to supress warnings.
    int st = 32767; unsigned int ut = st;
    t = st;
    BOOST_CHECK(lexical_cast<short>(t) == st);
    BOOST_CHECK(lexical_cast<unsigned short>(t) == ut);
    BOOST_CHECK(lexical_cast<int>(t) == st);
    BOOST_CHECK(lexical_cast<unsigned int>(t) == ut);
    BOOST_CHECK(lexical_cast<long>(t) == st);
    BOOST_CHECK(lexical_cast<unsigned long>(t) == ut);

    t = std::numeric_limits<T>::max();
    BOOST_CHECK(lexical_cast<T>(t) == t);

    t = std::numeric_limits<T>::min();
    BOOST_CHECK(lexical_cast<T>(t) == t);
}

template<class T, class CharT>
void test_conversion_from_integral_to_string(CharT)
{
    typedef std::numeric_limits<T> limits;
    typedef std::basic_string<CharT> string_type;

    T t;

    t = limits::min();
    BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));

    t = limits::max();
    BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));

    if(limits::digits <= 16 && lcast_test_small_integral_types_completely)
        for(t = 1 + limits::min(); t != limits::max(); ++t)
            BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));
    else
    {
        T const min_val = limits::min();
        T const max_val = limits::max();
        T const half_max_val = max_val / 2;
        T const cnt = lcast_integral_test_counter; // to supress warnings
        unsigned int const counter = cnt < half_max_val ? cnt : half_max_val;

        unsigned int i;

        // Test values around min:
        t = min_val;
        for(i = 0; i < counter; ++i, ++t)
            BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));

        // Test values around max:
        t = max_val;
        for(i = 0; i < counter; ++i, --t)
            BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));

        // Test values around zero:
        if(limits::is_signed)
            for(t = -counter; t < static_cast<T>(counter); ++t)
                BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));

        // Test values around 100, 1000, 10000, ...
        T ten_power = 100;
        for(int e = 2; e <= limits::digits10; ++e, ten_power *= 10)
        {
            // I believe that (ten_power + 100) never overflows
            for(t = ten_power - 100; t != ten_power + 100; ++t)
                BOOST_CHECK(lexical_cast<string_type>(t) == to_str<CharT>(t));
        }
    }
}

template<class T>
void test_conversion_from_integral_for_locale()
{
    test_conversion_from_integral_to_integral<T>();
    test_conversion_from_integral_to_string<T>('0');
#ifndef DISABLE_WIDE_CHAR_SUPPORT
    test_conversion_from_integral_to_string<T>(L'0');
#endif
}

struct restore_oldloc
{
    std::locale oldloc;
    ~restore_oldloc() { std::locale::global(oldloc); }
};

template<class T>
void test_conversion_from_integral()
{
    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_integral_to_char<T>(szero);
    test_conversion_from_integral_to_char<T>(uzero);
#ifndef DISABLE_WIDE_CHAR_SUPPORT
    wchar_t const wzero = L'0';
    test_conversion_from_integral_to_char<T>(wzero);
#endif

    // test_conversion_from_integral_for_locale

    typedef std::numpunct<char> numpunct;

    restore_oldloc guard;
    std::locale const& oldloc = guard.oldloc;

    std::string grouping1 = BOOST_USE_FACET(numpunct, oldloc).grouping();
    std::string grouping2(grouping1);

    test_conversion_from_integral_for_locale<T>();

    try
    {
        std::locale newloc("");
        std::locale::global(newloc);

        grouping2 = BOOST_USE_FACET(numpunct, newloc).grouping();
    }
    catch(std::exception const& ex)
    {
        std::string msg("Failed to set system locale: ");
        msg += ex.what();
        BOOST_TEST_MESSAGE(msg);
    }

    if(grouping1 != grouping2)
        test_conversion_from_integral_for_locale<T>();

    if(grouping1.empty() && grouping2.empty())
        BOOST_TEST_MESSAGE("Formatting with thousands_sep has not been tested");
}

void test_conversion_from_short()
{
    test_conversion_from_integral<short>();
}

void test_conversion_from_ushort()
{
    test_conversion_from_integral<unsigned short>();
}

void test_conversion_from_int()
{
    test_conversion_from_integral<int>();
}

void test_conversion_from_uint()
{
    test_conversion_from_integral<unsigned int>();
}

void test_conversion_from_ulong()
{
    test_conversion_from_integral<unsigned long>();
}

void test_conversion_from_long()
{
    test_conversion_from_integral<long>();
}

#if defined(BOOST_HAS_LONG_LONG)

void test_conversion_from_longlong()
{
    test_conversion_from_integral<boost::long_long_type>();
}

void test_conversion_from_ulonglong()
{
    test_conversion_from_integral<boost::ulong_long_type>();
}

#elif defined(LCAST_TEST_LONGLONG)

void test_conversion_from_longlong()
{
    test_conversion_from_integral<__int64>();
}

void test_conversion_from_ulonglong()
{
    test_conversion_from_integral<unsigned __int64>();
}

#endif

template<class T>
void test_round_conversion(bool use_min_max_values = true)
{
    T v1 = std::numeric_limits<T>::epsilon();
    std::string s1 = boost::lexical_cast<std::string>(v1);
    BOOST_CHECK(v1 == lexical_cast<T>(s1));

    if(use_min_max_values)
    {
        T v2 = (std::numeric_limits<T>::max)();
        std::string s2 = boost::lexical_cast<std::string>(v2);
        BOOST_CHECK(v2 == lexical_cast<T>(s2));

        T v3 = (std::numeric_limits<T>::min)();
        std::string s3 = boost::lexical_cast<std::string>(v3);
        BOOST_CHECK(v3 == lexical_cast<T>(s3));

        T v4 = v2 / 137;
        std::string s4 = boost::lexical_cast<std::string>(v4);
        BOOST_CHECK(v4 == lexical_cast<T>(s4));
    }

    T v5 = v1 * 137;
    std::string s5 = boost::lexical_cast<std::string>(v5);
    BOOST_CHECK(v5 == lexical_cast<T>(s5));
}

void test_round_conversion_float()
{
    test_round_conversion<float>();
}

void test_round_conversion_double()
{
    test_round_conversion<double>();
}

void test_round_conversion_long_double()
{
#if defined(BOOST_NO_STDLIB_CONFIG)
    test_round_conversion<long double>();
#elif defined(__i386__) && defined(__OpenBSD__)
    test_round_conversion<long double>(false);
#elif !defined(__i386__) || !defined(__FreeBSD__)
    test_round_conversion<long double>();
#endif
}