forked from OSchip/llvm-project
SFINAE out duration converting constructor if the constructor would otherwise cause a ratio compile-time overflow. This fixes LWG 2094.
llvm-svn: 189722
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@ -409,6 +409,37 @@ class _LIBCPP_TYPE_VIS_ONLY duration
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static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
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static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
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static_assert(_Period::num > 0, "duration period must be positive");
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template <class _R1, class _R2>
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struct __no_overflow
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{
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private:
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static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
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static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
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static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
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static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
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static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
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static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
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static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
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template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
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struct __mul // __overflow == false
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{
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static const intmax_t value = _Xp * _Yp;
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};
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template <intmax_t _Xp, intmax_t _Yp>
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struct __mul<_Xp, _Yp, true>
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{
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static const intmax_t value = 1;
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};
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public:
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static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
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typedef ratio<__mul<__n1, __d2, !value>::value,
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__mul<__n2, __d1, !value>::value> type;
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};
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public:
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typedef _Rep rep;
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typedef _Period period;
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@ -440,9 +471,10 @@ public:
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duration(const duration<_Rep2, _Period2>& __d,
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typename enable_if
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<
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__no_overflow<_Period2, period>::value && (
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treat_as_floating_point<rep>::value ||
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(ratio_divide<_Period2, period>::type::den == 1 &&
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!treat_as_floating_point<_Rep2>::value)
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(__no_overflow<_Period2, period>::type::den == 1 &&
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!treat_as_floating_point<_Rep2>::value))
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>::type* = 0)
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: __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
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@ -35,6 +35,8 @@ test(const FromDuration& df, const ToDuration& d)
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}
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}
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#if _LIBCPP_STD_VER > 11
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template<class FromDuration, long long From, class ToDuration, long long To>
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void test_constexpr ()
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{
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@ -49,6 +51,8 @@ void test_constexpr ()
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}
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#endif
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int main()
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{
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test(std::chrono::milliseconds(7265000), std::chrono::hours(2));
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@ -140,7 +140,7 @@
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2091">2091</a></td><td>Misplaced effect in m.try_lock_for()</td><td>Bristol</td><td>Complete</td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2092">2092</a></td><td>Vague Wording for condition_variable_any</td><td>Bristol</td><td>Complete</td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2093">2093</a></td><td>Throws clause of condition_variable::wait with predicate</td><td>Bristol</td><td>Complete</td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2094">2094</a></td><td>duration conversion overflow shouldn't participate in overload resolution</td><td>Bristol</td><td></td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2094">2094</a></td><td>duration conversion overflow shouldn't participate in overload resolution</td><td>Bristol</td><td>Complete</td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2122">2122</a></td><td>merge() stability for lists versus forward lists</td><td>Bristol</td><td></td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2128">2128</a></td><td>Absence of global functions cbegin/cend</td><td>Bristol</td><td>Complete</td></tr>
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<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2145">2145</a></td><td>error_category default constructor</td><td>Bristol</td><td>Complete</td></tr>
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