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Clean up pairwise_all() and strictly_increasing()

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This commit is contained in:
Chip Hogg
2022-01-08 14:28:53 -05:00
parent 92b7a15d6f
commit 3063aebe5a
2 changed files with 40 additions and 36 deletions
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src/core/include/units/magnitude.h
+21 -13
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@@ -176,23 +176,31 @@ constexpr auto pi_to_the() { return magnitude<pi_power<Power>()>{}; }
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Magnitude concept implementation.
template<typename Predicate, typename... Ts>
constexpr bool pairwise_all(const std::tuple<Ts...> &ts, const Predicate &pred) {
// Carefully handle different sizes, avoiding unsigned integer underflow.
constexpr auto num_comparisons = [](auto num_elements) {
return (num_elements > 1) ? (num_elements - 1) : 0;
}(sizeof...(Ts));
template<typename Predicate>
struct pairwise_all {
Predicate predicate;
// Compare zero or more pairs of neighbours as needed.
return [&ts, &pred]<std::size_t... Is>(std::integer_sequence<std::size_t, Is...>) {
return (pred(std::get<Is>(ts), std::get<Is + 1>(ts)) && ...);
}(std::make_index_sequence<num_comparisons>());
}
template<typename... Ts>
constexpr bool operator()(Ts&&... ts) const {
// Carefully handle different sizes, avoiding unsigned integer underflow.
constexpr auto num_comparisons = [](auto num_elements) {
return (num_elements > 1) ? (num_elements - 1) : 0;
}(sizeof...(Ts));
// Compare zero or more pairs of neighbours as needed.
return [this]<std::size_t... Is>(std::tuple<Ts...> &&t, std::index_sequence<Is...>) {
return (predicate(std::get<Is>(t), std::get<Is + 1>(t)) && ...);
}(std::make_tuple(std::forward<Ts>(ts)...), std::make_index_sequence<num_comparisons>());
}
};
template<typename T>
pairwise_all(T) -> pairwise_all<T>;
// Check whether a tuple of (possibly heterogeneously typed) values are strictly increasing.
template<typename... Ts>
constexpr bool strictly_increasing(const std::tuple<Ts...> &ts) {
return pairwise_all(ts, std::less{});
constexpr bool strictly_increasing(Ts&&... ts) {
return pairwise_all{std::less{}}(std::forward<Ts>(ts)...);
}
namespace detail