Merge pull request #1759 from evoskuil/master

Add is_empty_tuple, is_shared_ptr, tests.

Author: evoskuil

include/bitcoin/system/typelets.hpp

@@ -163,12 +163,30 @@ constexpr bool is_tuple = is_tuple_t<Type>::value;
 
 template <typename Tuple>
 struct decay_tuple;
-
 template <typename ...Args>
 struct decay_tuple<std::tuple<Args...>>
 {
     using type = std::tuple<std::decay_t<Args>...>;
 };
+template <typename Tuple>
+using decay_tuple_t = typename decay_tuple<Tuple>::type;
+
+template <typename Left, typename Right>
+constexpr bool is_same_tuple = is_same_type<decay_tuple_t<Left>,
+    decay_tuple_t<Right>>;
+
+template <typename Tuple>
+constexpr bool is_empty_tuple = is_zero(std::tuple_size_v<Tuple>);
+
+/// std::shared_ptr<> detection.
+/// ---------------------------------------------------------------------------
+
+template <typename Type>
+struct is_shared_ptr_t : std::false_type {};
+template <typename Type>
+struct is_shared_ptr_t<std::shared_ptr<Type>> : std::true_type {};
+template <typename Type>
+constexpr bool is_shared_ptr = is_shared_ptr_t<std::decay_t<Type>>::value;
 
 /// uintx_t detection.
 /// ---------------------------------------------------------------------------

test/typelets.cpp

@@ -470,7 +470,36 @@ static_assert(!std::is_same_v<std::tuple_element<0, decayed_test_tuple>::type, i
 static_assert(!std::is_same_v<std::tuple_element<1, decayed_test_tuple>::type, bool&&>);
 static_assert(!std::is_same_v<std::tuple_element<2, decayed_test_tuple>::type, std::string&&>);
 
-// is_uintx
+static_assert( is_same_tuple<std::tuple<char* const&, double&&>, std::tuple<char*, double>>);
+static_assert(!is_same_tuple<std::tuple<int, double>, std::tuple<int, float>>);
+static_assert(!is_same_tuple<std::tuple<const char*>, std::tuple<int>>);
+static_assert(!is_same_tuple<std::tuple<int, double>, std::tuple<int>>);
+static_assert(!is_same_tuple<std::tuple<>, std::tuple<int>>);
+static_assert( is_same_tuple<std::tuple<>, std::tuple<>>);
+static_assert( is_same_tuple<std::tuple<int, double>, std::tuple<int, double>>);
+static_assert( is_same_tuple<std::tuple<int[5], void(*)(int)>, std::tuple<int*, void(*)(int)>>);
+static_assert(!is_same_tuple<std::tuple<char*, const char* const&>, std::tuple<char*, char*>>);
+
+static_assert( is_empty_tuple<std::tuple<>>);
+static_assert(!is_empty_tuple<std::tuple<bool>>);
+
+// std::shared_ptr<>
+// ----------------------------------------------------------------------------
+
+static_assert( is_shared_ptr<std::shared_ptr<int>>);
+static_assert(!is_shared_ptr<std::unique_ptr<int>>);
+static_assert(!is_shared_ptr<std::weak_ptr<int>>);
+static_assert(!is_shared_ptr<int*>);
+static_assert(!is_shared_ptr<int>);
+static_assert( is_shared_ptr<const std::shared_ptr<double>>);
+static_assert( is_shared_ptr<const std::shared_ptr<double>&>);
+static_assert( is_shared_ptr<std::shared_ptr<double> const&>);
+static_assert( is_shared_ptr<std::shared_ptr<std::string>>);
+static_assert( is_shared_ptr<std::shared_ptr<const std::string>>);
+static_assert( is_shared_ptr<std::shared_ptr<const std::string&>>);
+static_assert(!is_shared_ptr<std::vector<int>>);
+
+// uintx_t
 // ----------------------------------------------------------------------------
 
 static_assert(is_uintx<uint5_t>);