62 lines
1.5 KiB
C++
62 lines
1.5 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// <optional>
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// template <class T> constexpr bool operator<(const optional<T>& x, const T& v);
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// template <class T> constexpr bool operator<(const T& v, const optional<T>& x);
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#include <experimental/optional>
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#if _LIBCPP_STD_VER > 11
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using std::experimental::optional;
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struct X
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{
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int i_;
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constexpr X(int i) : i_(i) {}
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};
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constexpr bool operator < ( const X &lhs, const X &rhs )
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{ return lhs.i_ < rhs.i_ ; }
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#endif
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int main()
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{
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#if _LIBCPP_STD_VER > 11
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{
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typedef X T;
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typedef optional<T> O;
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constexpr T val(2);
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constexpr O o1; // disengaged
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constexpr O o2{1}; // engaged
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constexpr O o3{val}; // engaged
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static_assert ( o1 < T(1) , "" );
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static_assert ( !(o2 < T(1)), "" );
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static_assert ( !(o3 < T(1)), "" );
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static_assert ( o2 < T(2) , "" );
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static_assert ( o2 < T(val), "" );
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static_assert ( o3 < T(3) , "" );
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static_assert ( !(T(1) < o1), "" );
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static_assert ( !(T(1) < o2), "" );
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static_assert ( T(1) < o3 , "" );
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static_assert ( !(T(2) < o2), "" );
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static_assert (!(T(val) < o2), "" );
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static_assert ( !(T(3) < o3), "" );
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}
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#endif
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}
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