From 199db7640eb36ac347e8f3a25b89ab16333a3400 Mon Sep 17 00:00:00 2001
From: King_DuckZ <king_duckz@gmx.com>
Date: Sat, 29 May 2021 16:47:48 +0200
Subject: [PATCH] Add support for int_conv<std::array>()

---
 .../implem/reversed_sized_array_bt.hpp         | 16 ++++++++++++++++
 include/duckhandy/int_conv.hpp                 | 18 ++++++++++++++++++
 test/unit/int_conv_test.cpp                    | 17 +++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/include/duckhandy/implem/reversed_sized_array_bt.hpp b/include/duckhandy/implem/reversed_sized_array_bt.hpp
index 30fcc80..225c817 100644
--- a/include/duckhandy/implem/reversed_sized_array_bt.hpp
+++ b/include/duckhandy/implem/reversed_sized_array_bt.hpp
@@ -26,6 +26,7 @@
 #	include <string>
 #	include <sstream>
 #endif
+#include <tuple>
 
 namespace dhandy {
 	template <typename T, std::size_t S>
@@ -33,6 +34,8 @@ namespace dhandy {
 		static_assert(S > 0, "This container requires size to be at least 1");
 		static_assert(std::is_trivial<T>::value, "Only use this container with trivial types");
 	public:
+		constexpr static const std::size_t capacity = S;
+
 		using iterator = typename std::array<T, S>::iterator;
 		constexpr ReversedSizedArray() = default;
 		~ReversedSizedArray() = default;
@@ -49,6 +52,7 @@ namespace dhandy {
 
 		template <typename V>
 		constexpr V to() const { return V(data(), size() - (not empty() and not back() ? 1 : 0)); }
+		constexpr auto to_tuple() const;
 
 #if !defined(INT_CONV_WITHOUT_HELPERS)
 		constexpr std::basic_string_view<T> to_string_view() const { return to<std::basic_string_view<T>>(); }
@@ -65,6 +69,13 @@ namespace dhandy {
 		std::size_t m_curr {S - 1};
 	};
 
+	namespace implem {
+		template <typename T, std::size_t S, std::size_t... Indices>
+		constexpr auto elements_or_empty_to_tuple (const std::array<T, S>& elems, std::size_t from_idx, std::index_sequence<Indices...>) {
+			return std::make_tuple((from_idx + Indices < S ? elems[from_idx + Indices] : T{})...);
+		}
+	} //namespace implem
+
 #if !defined(INT_CONV_WITHOUT_HELPERS)
 	template <typename T, std::size_t S>
 	inline
@@ -73,6 +84,11 @@ namespace dhandy {
 		return stream;
 	}
 #endif
+
+	template <typename T, std::size_t S>
+	constexpr auto ReversedSizedArray<T, S>::to_tuple() const {
+		return implem::elements_or_empty_to_tuple(m_data, m_curr + 1, std::make_index_sequence<S>{});
+	}
 } //namespace dhandy
 
 #endif
diff --git a/include/duckhandy/int_conv.hpp b/include/duckhandy/int_conv.hpp
index b7edd46..1e31501 100644
--- a/include/duckhandy/int_conv.hpp
+++ b/include/duckhandy/int_conv.hpp
@@ -22,6 +22,7 @@
 #include <type_traits>
 #include <string>
 #include <string_view>
+#include <array>
 
 namespace dhandy {
 	namespace implem {
@@ -47,6 +48,23 @@ namespace dhandy {
 				return dhandy::int_to_ary<F, 10, Tr>(in).to_string_view();
 			}
 		};
+		template <typename F, typename Tr, typename C, std::size_t N>
+		struct IntConv<std::array<C, N>, F, Tr, true> {
+		private:
+			template <typename... Args, std::size_t... Indices>
+			constexpr static std::array<C, N> to_array (const std::tuple<Args...>& vals, std::index_sequence<Indices...>) {
+				return std::array<C, N>{std::get<Indices>(vals)...};
+			}
+		public:
+			constexpr static std::array<C, N> conv (const F& in) {
+				return to_array(
+					dhandy::int_to_ary<F, 10, Tr>(in).to_tuple(),
+					std::make_index_sequence<
+						std::min(decltype(dhandy::int_to_ary<F, 10, Tr>(in))::capacity, N)
+					>{}
+				);
+			}
+		};
 		template <typename T, typename Tr>
 		struct IntConv<T, IntConvString<Tr>, Tr, false> {
 			constexpr static T conv (const IntConvString<Tr>& in) {
diff --git a/test/unit/int_conv_test.cpp b/test/unit/int_conv_test.cpp
index d187ae7..1bd46ce 100644
--- a/test/unit/int_conv_test.cpp
+++ b/test/unit/int_conv_test.cpp
@@ -224,6 +224,23 @@ TEST_CASE ("Check string_view conversions work as expected", "[i2s][int_conv]")
 	CHECK("123" == str123);
 }
 
+TEST_CASE ("Check std::array conversion works as expected", "[i2s][int_conv]") {
+	using std::array;
+	using dhandy::int_conv;
+
+	auto arr748 = int_conv<array<char, 3>>(748);
+	CHECK(arr748[0] == '7');
+	CHECK(arr748[1] == '4');
+	CHECK(arr748[2] == '8');
+
+	auto arr19000 = int_conv<array<char, 5>>(19);
+	CHECK(arr19000[0] == '1');
+	CHECK(arr19000[1] == '9');
+	CHECK(arr19000[2] == '\0');
+	CHECK(arr19000[3] == '\0');
+	CHECK(arr19000[4] == '\0');
+}
+
 TEST_CASE ("Check upcase/downcase int to array conversions", "[i2s][int_conv]") {
 	using dhandy::int_conv;
 	using std::string_view;