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// PR c++/107542
// { dg-do compile { target c++20 } }
#include <compare>
template<class T, class U>
concept same_as = __is_same(T, U);
template<class Lhs, class Rhs>
concept Ord = requires(Lhs lhs, Rhs rhs) {
{ lhs <=> rhs } -> same_as<std::strong_ordering>;
};
static_assert(Ord<int*, int*>); // Works.
static_assert(!Ord<int*, char*>); // ICE.
template<class T>
struct S {
T* p;
};
template<class T, class U>
requires(Ord<const T*, const U*>)
constexpr inline auto operator<=>(const S<T>& l, const S<U>& r) noexcept {
return l.p <=> r.p;
}
static_assert(Ord<S<int>, S<int>>); // Works.
static_assert(!Ord<S<int>, S<char>>); // ICE.
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