ceph/src/boost/libs/spirit/test/qi/extract_int.cpp

   1 /*=============================================================================
   2   Copyright (c) 2018 Nikita Kniazev
   3
   4   Distributed under the Boost Software License, Version 1.0. (See accompanying
   5   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7
   8 #include <boost/detail/lightweight_test.hpp>
   9 #include <boost/spirit/home/qi/numeric/numeric_utils.hpp>
  10 #include <boost/static_assert.hpp>
  11 #include <cmath> // for std::pow
  12 #include <iosfwd>
  13 #include <limits>
  14 #include <sstream>
  15
  16 #ifdef _MSC_VER
  17 # pragma warning(disable: 4127) // conditional expression is constant
  18 #endif
  19
  20 template <int Min, int Max>
  21 struct custom_int
  22 {
  23     BOOST_DEFAULTED_FUNCTION(custom_int(), {})
  24     BOOST_CONSTEXPR custom_int(int value) : value_(value) {}
  25
  26     custom_int operator+(custom_int x) const { return value_ + x.value_; }
  27     custom_int operator-(custom_int x) const { return value_ - x.value_; }
  28     custom_int operator*(custom_int x) const { return value_ * x.value_; }
  29     custom_int operator/(custom_int x) const { return value_ / x.value_; }
  30
  31     custom_int& operator+=(custom_int x) { value_ += x.value_; return *this; }
  32     custom_int& operator-=(custom_int x) { value_ -= x.value_; return *this; }
  33     custom_int& operator*=(custom_int x) { value_ *= x.value_; return *this; }
  34     custom_int& operator/=(custom_int x) { value_ /= x.value_; return *this; }
  35     custom_int& operator++() { ++value_; return *this; }
  36     custom_int& operator--() { --value_; return *this; }
  37     custom_int operator++(int) { return value_++; }
  38     custom_int operator--(int) { return value_--; }
  39
  40     custom_int operator+() { return +value_; }
  41     custom_int operator-() { return -value_; }
  42
  43     bool operator< (custom_int x) const { return value_ <  x.value_; }
  44     bool operator> (custom_int x) const { return value_ >  x.value_; }
  45     bool operator<=(custom_int x) const { return value_ <= x.value_; }
  46     bool operator>=(custom_int x) const { return value_ >= x.value_; }
  47     bool operator==(custom_int x) const { return value_ == x.value_; }
  48     bool operator!=(custom_int x) const { return value_ != x.value_; }
  49
  50     template <typename Char, typename Traits>
  51     friend std::basic_ostream<Char, Traits>&
  52     operator<<(std::basic_ostream<Char, Traits>& os, custom_int x) {
  53         return os << x.value_;
  54     }
  55
  56     BOOST_STATIC_CONSTEXPR int max = Max;
  57     BOOST_STATIC_CONSTEXPR int min = Min;
  58
  59 private:
  60     int value_;
  61 };
  62
  63 namespace utils {
  64
  65 template <int Min, int Max> struct digits;
  66 template <> struct digits<-9,  9>  { BOOST_STATIC_CONSTEXPR int r2 = 3, r10 = 1; };
  67 template <> struct digits<-10, 10> { BOOST_STATIC_CONSTEXPR int r2 = 3, r10 = 1; };
  68 template <> struct digits<-15, 15> { BOOST_STATIC_CONSTEXPR int r2 = 3, r10 = 1; };
  69
  70 }
  71
  72 namespace std {
  73
  74 template <int Min, int Max>
  75 class numeric_limits<custom_int<Min, Max> > : public numeric_limits<int>
  76 {
  77 public:
  78     static BOOST_CONSTEXPR custom_int<Min, Max> max() BOOST_NOEXCEPT_OR_NOTHROW { return Max; }
  79     static BOOST_CONSTEXPR custom_int<Min, Max> min() BOOST_NOEXCEPT_OR_NOTHROW { return Min; }
  80     static BOOST_CONSTEXPR custom_int<Min, Max> lowest() BOOST_NOEXCEPT_OR_NOTHROW { return min(); }
  81     BOOST_STATIC_ASSERT_MSG(numeric_limits<int>::radix == 2, "hardcoded for digits of radix 2");
  82     BOOST_STATIC_CONSTEXPR int digits = utils::digits<Min, Max>::r2;
  83     BOOST_STATIC_CONSTEXPR int digits10 = utils::digits<Min, Max>::r10;
  84 };
  85
  86 }
  87
  88 namespace qi = boost::spirit::qi;
  89
  90 template <typename T, int Base, int MaxDigits>
  91 void test_overflow_handling(char const* begin, char const* end, int i)
  92 {
  93     // Check that parser fails on overflow
  94     BOOST_STATIC_ASSERT_MSG(std::numeric_limits<T>::is_bounded, "tests prerequest");
  95     BOOST_ASSERT_MSG(MaxDigits == -1 || static_cast<int>(std::pow(float(Base), MaxDigits)) > T::max,
  96                      "test prerequest");
  97     int initial = Base - i % Base; // just a 'random' non-equal to i number
  98     T x(initial);
  99     char const* it = begin;
 100     bool r = qi::extract_int<T, Base, 1, MaxDigits>::call(it, end, x);
 101     if (T::min <= i && i <= T::max) {
 102         BOOST_TEST(r);
 103         BOOST_TEST(it == end);
 104         BOOST_TEST_EQ(x, i);
 105     }
 106     else {
 107         BOOST_TEST(!r);
 108         BOOST_TEST(it == begin);
 109     }
 110 }
 111
 112 template <typename T, int Base>
 113 void test_unparsed_digits_are_not_consumed(char const* it, char const* end, int i)
 114 {
 115     // Check that unparsed digits are not consumed
 116     BOOST_STATIC_ASSERT_MSG(T::min <= -Base+1, "test prerequest");
 117     BOOST_STATIC_ASSERT_MSG(T::max >=  Base-1, "test prerequest");
 118     bool has_sign = *it == '+' || *it == '-';
 119     char const* begin = it;
 120     int initial = Base - i % Base; // just a 'random' non-equal to i number
 121     T x(initial);
 122     bool r = qi::extract_int<T, Base, 1, 1>::call(it, end, x);
 123     BOOST_TEST(r);
 124     if (-Base < i && i < Base) {
 125         BOOST_TEST(it == end);
 126         BOOST_TEST_EQ(x, i);
 127     }
 128     else {
 129         BOOST_TEST_EQ(end - it, (end - begin) - 1 - has_sign);
 130         BOOST_TEST_EQ(x, i / Base);
 131     }
 132 }
 133
 134 template <typename T, int Base>
 135 void test_ignore_overflow_digits(char const* it, char const* end, int i)
 136 {
 137     // TODO: Check accumulating too?
 138     if (i < 0) return; // extract_int does not support IgnoreOverflowDigits
 139
 140     bool has_sign = *it == '+' || *it == '-';
 141     char const* begin = it;
 142     int initial = Base - i % Base; // just a 'random' non-equal to i number
 143     T x(initial);
 144     BOOST_TEST((qi::extract_uint<T, Base, 1, -1, false, true>::call(it, end, x)));
 145     if (T::min <= i && i <= T::max) {
 146         BOOST_TEST(it == end);
 147         BOOST_TEST_EQ(x, i);
 148     }
 149     else {
 150         BOOST_TEST_EQ(it - begin, (qi::detail::digits_traits<T, Base>::value) + has_sign);
 151         if (Base == std::numeric_limits<T>::radix)
 152             BOOST_TEST_EQ(it - begin, std::numeric_limits<T>::digits + has_sign);
 153         if (Base == 10)
 154             BOOST_TEST_EQ(it - begin, std::numeric_limits<T>::digits10 + has_sign);
 155         int expected = i;
 156         for (char const* p = it; p < end; ++p) expected /= Base;
 157         BOOST_TEST_EQ(x, expected);
 158     }
 159 }
 160
 161 template <typename T, int Base>
 162 void run_tests(char const* begin, char const* end, int i)
 163 {
 164     // Check that parser fails on overflow
 165     test_overflow_handling<T, Base, -1>(begin, end, i);
 166     // Check that MaxDigits > digits10 behave like MaxDigits=-1
 167     test_overflow_handling<T, Base, 2>(begin, end, i);
 168     // Check that unparsed digits are not consumed
 169     test_unparsed_digits_are_not_consumed<T, Base>(begin, end, i);
 170     // Check that IgnoreOverflowDigits does what we expect
 171     test_ignore_overflow_digits<T, Base>(begin, end, i);
 172 }
 173
 174 int main()
 175 {
 176     for (int i = -30; i <= 30; ++i) {
 177         std::ostringstream oss;
 178         oss << i;
 179         std::string s = oss.str();
 180         char const* begin = s.data(), *const end = begin + s.size();
 181
 182         // log(Base, abs(MinOrMax) + 1) == digits
 183         run_tests<custom_int<-9, 9>, 10>(begin, end, i);
 184         // (MinOrMax % Base) == 0
 185         run_tests<custom_int<-10, 10>, 10>(begin, end, i);
 186         // (MinOrMax % Base) != 0
 187         run_tests<custom_int<-15, 15>, 10>(begin, end, i);
 188     }
 189
 190     return boost::report_errors();
 191 }