Changing return types on data functions

10 files changed, 177 insertions, 149 deletions

diff --git a/modules/codec/c++/base64.hpp b/modules/codec/c++/base64.hpp
index 141a63d..ce9d4ce 100644
--- a/modules/codec/c++/base64.hpp
+++ b/modules/codec/c++/base64.hpp
@@ -71,8 +71,8 @@ public:
 		std::string b64_str;
 
 		try {
-			uint64_t unpadded_len = (from.size() * 4u + 2u) / 3u;
-			uint64_t padded_len = ( unpadded_len + 3u ) & ~3u;
+			uint64_t unpadded_len = (from.size() * 4u + 2u).get() / 3u;
+			uint64_t padded_len = (unpadded_len + 3u) & ~3u;
 			b64_str.resize(padded_len);
 		}catch(const std::exception&){
 			return make_error<err::out_of_memory>();
@@ -81,8 +81,8 @@ public:
 		uint64_t j{0u}, k{0u};
 		std::array<uint8_t,3> s{};
 
-		for(uint64_t i = 0u; i < from.size(); ++i){
-			s[j] = from.at(i);
+		for(data<schema::UInt64> i = 0u; i < from.size(); ++i){
+			s[j] = from.at(i.get());
 			++j;
 			if(j==3){
 				b64_str.at(k) = impl::base64_char_map.at((s[0u] & 0xFC) >> 2);
diff --git a/modules/codec/c++/csv.hpp b/modules/codec/c++/csv.hpp
index 240ed75..0d76372 100644
--- a/modules/codec/c++/csv.hpp
+++ b/modules/codec/c++/csv.hpp
@@ -50,7 +50,7 @@ struct csv_encode<schema::Array<T,Dim>, FromDecode> {
 			}
 		}
 
-		for(std::size_t i = 0; i < from.size(); ++i){
+		for(data<schema::UInt64> i = 0; i < from.size(); ++i){
 			auto eov = csv_encode<T,FromDecode>::encode(from.at(i), to);
 			if(eov.is_error()){
 				return eov;
@@ -166,8 +166,8 @@ struct csv_encode<schema::String, FromDecode> {
 	using Schema = schema::String;
 
 	static error_or<void> encode(const data<Schema, FromDecode>& from, buffer& to){
-		for(size_t i = 0; i < from.size(); ++i){
-			auto eov = stream_value<schema::Int8>::encode(from.at(i), to);
+		for(data<schema::UInt64> i = 0; i < from.size(); ++i){
+			auto eov = stream_value<schema::Int8>::encode(from.at(i.get()), to);
 			if(eov.is_error()){
 				return eov;
 			}
diff --git a/modules/codec/c++/data.hpp b/modules/codec/c++/data.hpp
index 75c611c..01eddb6 100644
--- a/modules/codec/c++/data.hpp
+++ b/modules/codec/c++/data.hpp
@@ -167,6 +167,11 @@ public:
 		return {get() - rhs.get()};
 	}
 
+	data<Schema, encode::Native>& operator++() {
+		set(get() + static_cast<typename native_data_type<Schema>::type>(1));
+		return *this;
+	}
+
 	template<typename Enc>
 	bool operator==(const data<Schema, Enc>& rhs)const{
 		return get() == rhs.get();
@@ -271,6 +276,74 @@ public:
 	}
 };
 
+template<typename T, uint64_t... D>
+class data<schema::FixedArray<T,D...>, encode::Native> {
+public:
+	using Schema = schema::FixedArray<T,D...>;
+	using MetaSchema = typename meta_schema<Schema>::MetaSchema;
+private:
+	//using inner_type = std::array<data<T, encode::Native>, multiply_helper<Dims...>::value>;
+	//std::unique_ptr<inner_type> value_;
+	using ArrayT = std::array<data<T, encode::Native>, ct_multiply<uint64_t, D...>::value>;
+	ArrayT value_;
+	
+public:
+	data() = default;
+	data(data<MetaSchema, encode::Native>){}
+	data(const std::array<data<T, encode::Native>, ct_multiply<uint64_t,D...>::value>& value__):
+		value_{value__}
+	{}
+
+	data<T, encode::Native>& at(const std::array<uint64_t, sizeof...(D)>& ind){
+		return value_.at(this->get_flat_index(ind));
+	}
+		
+	const data<T, encode::Native>& at(const std::array<uint64_t, sizeof...(D)>& ind) const {
+		return value_.at(this->get_flat_index(ind));
+	}
+	
+	data<T, encode::Native>& at(data<schema::UInt64, encode::Native> i) {
+		return value_.at(this->get_flat_index({i.get()}));
+	}
+	
+	const data<T, encode::Native>& at(data<schema::UInt64, encode::Native> i) const {
+		return value_.at(this->get_flat_index({i.get()}));
+	}
+
+	data<T, encode::Native>& at(const data<schema::FixedArray<schema::UInt64, sizeof...(D)>>& i){
+		return value_.at(this->get_flat_index(i));
+	}
+	
+	const data<T, encode::Native>& at(const data<schema::FixedArray<schema::UInt64, sizeof...(D)>>& i)const{
+		return value_.at(this->get_flat_index(i));
+	}
+
+	template<uint64_t i>
+	uint64_t get_dim_size() const {
+		return parameter_pack_value<i, uint64_t, D...>::value;
+	}
+
+	data<schema::FixedArray<schema::UInt64, sizeof...(D)>> get_dims() const {
+		return {std::array<uint64_t, sizeof...(D)>{D...}};
+	}
+private:
+	uint64_t get_flat_index(const std::array<uint64_t, sizeof...(D)>& i) const {
+		uint64_t s = 0;
+
+		uint64_t stride = 1;
+
+		constexpr static std::array<uint64_t, sizeof...(D)> dims_{D...};
+
+		for(uint64_t iter = 0; iter < sizeof...(D); ++iter){
+			assert(i.at(iter) < dims_.at(iter));
+			s += i.at(iter) * stride;
+			stride *= dims_.at(iter);
+		}
+
+		return s;
+	}
+};
+
 /* 
 template<typename T, typename N>
 class data<schema::Ref<schema::Primitive<T,N>>, encode::Native {
@@ -427,7 +500,7 @@ public:
 	/**
 	 * Return the amount of members.
 	 */
-	constexpr size_t size() const {
+	constexpr uint64_t size() const {
 		return sizeof...(T);
 	}
 };
@@ -474,7 +547,7 @@ public:
 		return std::get<i>(value_);
 	}
 
-	constexpr size_t size() const {
+	constexpr uint64_t size() const {
 		return sizeof...(T);
 	}
 };
@@ -609,15 +682,17 @@ class data<schema::Array<T,Dim>, encode::Native> {
 		const data<T, encode::Native>& at(const std::array<uint64_t, Dim>& ind) const {
 			return value_.at(this->get_flat_index(ind));
 		}
-
-		template<std::integral... Dims>
-		data<T, encode::Native>& at(Dims... i){
-			return value_.at(this->get_flat_index(std::array<uint64_t, Dim>{static_cast<uint64_t>(i)...}));
-		}
 		
-		template<std::integral... Dims>
-		const data<T, encode::Native>& at(Dims... i) const {
-			return value_.at(this->get_flat_index(std::array<uint64_t, Dim>{static_cast<uint64_t>(i)...}));
+		data<T, encode::Native>& at(data<schema::UInt64, encode::Native> i) {
+			data<schema::FixedArray<schema::UInt64,Dim>, encode::Native> i_arr;
+			i_arr.at(0u) = i;
+			return at(i_arr);
+		}
+	
+		const data<T, encode::Native>& at(data<schema::UInt64, encode::Native> i) const {
+			data<schema::FixedArray<schema::UInt64,Dim>, encode::Native> i_arr;
+			i_arr.at(0u) = i;
+			return at(i_arr);
 		}
 
 		data<T,encode::Native>& at(const data<schema::FixedArray<schema::UInt64,Dim>>& i){
@@ -632,7 +707,7 @@ class data<schema::Array<T,Dim>, encode::Native> {
 			return dims_.at(i);
 		}
 
-		size_t size() const { return value_.size();}
+		data<schema::UInt64,encode::Native> size() const { return {value_.size()};}
 
 		data<schema::FixedArray<schema::UInt64, Dim>> get_dims() const {
 			return {dims_};
@@ -662,7 +737,7 @@ private:
 						static_assert(always_false<V>, "Cases exhausted");
 					}
 				}(i.at(iter));
-				assert(ind < dims_.at(iter));
+				assert(ind < dims_.at({iter}));
 				s += ind * stride;
 				stride *= dims_.at(iter);
 			}
@@ -671,85 +746,6 @@ private:
 		}
 };
 
-template<typename T, uint64_t... D>
-class data<schema::FixedArray<T,D...>, encode::Native> {
-public:
-	using Schema = schema::FixedArray<T,D...>;
-	using MetaSchema = typename meta_schema<Schema>::MetaSchema;
-private:
-	//using inner_type = std::array<data<T, encode::Native>, multiply_helper<Dims...>::value>;
-	//std::unique_ptr<inner_type> value_;
-	using ArrayT = std::array<data<T, encode::Native>, ct_multiply<uint64_t, D...>::value>;
-	ArrayT value_;
-	
-public:
-	data() = default;
-	data(data<MetaSchema, encode::Native>){}
-	data(const std::array<data<T, encode::Native>, ct_multiply<uint64_t,D...>::value>& value__):
-		value_{value__}
-	{}
-
-	data<T, encode::Native>& at(const std::array<uint64_t, sizeof...(D)>& ind){
-		return value_.at(this->get_flat_index(ind));
-	}
-		
-	const data<T, encode::Native>& at(const std::array<uint64_t, sizeof...(D)>& ind) const {
-		return value_.at(this->get_flat_index(ind));
-	}
-	
-	template<typename... Sch>
-	data<T, encode::Native>& at(data<Sch, encode::Native>... i) {
-		return value_.at(this->get_flat_index({i...}));
-	}
-	
-	template<typename... Sch>
-	const data<T, encode::Native>& at(data<Sch, encode::Native>... i) const {
-		return value_.at(this->get_flat_index({i...}));
-	}
-
-	template<std::integral... Dims>
-	data<T, encode::Native>& at(Dims... i) {
-		return value_.at(this->get_flat_index({i...}));
-	}
-
-	template<std::integral... Dims>
-	const data<T, encode::Native>& at(Dims... i) const {
-		return value_.at(this->get_flat_index({i...}));
-	}
-
-	data<T, encode::Native>& at(const data<schema::FixedArray<schema::UInt64, sizeof...(D)>>& i){
-		return value_.at(this->get_flat_index(i));
-	}
-	
-	const data<T, encode::Native>& at(const data<schema::FixedArray<schema::UInt64, sizeof...(D)>>& i)const{
-		return value_.at(this->get_flat_index(i));
-	}
-
-	template<uint64_t i>
-	uint64_t get_dim_size() const {
-		return parameter_pack_value<i, uint64_t, D...>::value;
-	}
-
-	data<schema::FixedArray<schema::UInt64, sizeof...(D)>> get_dims() const {
-		return {std::array<uint64_t, sizeof...(D)>{D...}};
-	}
-private:
-	uint64_t get_flat_index(const std::array<uint64_t, sizeof...(D)>& i) const {
-		uint64_t s = 0;
-
-		uint64_t stride = 1;
-
-		constexpr static std::array<uint64_t, sizeof...(D)> dims_{D...};
-
-		for(uint64_t iter = 0; iter < sizeof...(D); ++iter){
-			assert(i.at(iter) < dims_.at(iter));
-			s += i.at(iter) * stride;
-			stride *= dims_.at(iter);
-		}
-
-		return s;
-	}
-};
 
 /**
  * Data type representing string.
@@ -781,8 +777,8 @@ public:
 	/**
 	 * Return the length of the string.
 	 */
-	std::size_t size() const {
-		return value_.size();
+	data<schema::UInt64, encode::Native> size() const {
+		return {value_.size()};
 	}
 
 	/**
@@ -795,22 +791,22 @@ public:
 	/**
 	 * Get a char reference at position i.
 	 */
-	char& at(size_t i) {
+	char& at(uint64_t i) {
 		return value_.at(i);
 	}
 
 	/**
 	 * Get a char reference at position i.
 	 */
-	const char& at(size_t i) const {
+	const char& at(uint64_t i) const {
 		return value_.at(i);
 	}
 
-	char get_at(size_t i) const{
+	char get_at(uint64_t i) const{
 		return value_.at(i);
 	}
 
-	void set_at(size_t i, char val){
+	void set_at(uint64_t i, char val){
 		value_.at(i) = val;
 	}
 
@@ -828,8 +824,8 @@ public:
 			return false;
 		}
 		bool eq = true;
-		for(uint64_t i = 0; i < size(); ++i){
-			eq = eq && (get_at(i) == rhs.get_at(i));
+		for(data<schema::UInt64, encode::Native> i = 0; i < size(); ++i){
+			eq = eq && (get_at(i.get()) == rhs.get_at(i.get()));
 		}
 		return eq;
 	}
diff --git a/modules/codec/c++/schema_meta.hpp b/modules/codec/c++/schema_meta.hpp
index 80b6686..659250c 100644
--- a/modules/codec/c++/schema_meta.hpp
+++ b/modules/codec/c++/schema_meta.hpp
@@ -78,9 +78,9 @@ struct meta_schema<schema::Array<T,Dim>> {
 	using Schema = schema::Array<T,Dim>;
 };
 
-template<typename T, uint64_t Dim>
-struct meta_schema<schema::FixedArray<T,Dim>> {
+template<typename T, uint64_t... Dim>
+struct meta_schema<schema::FixedArray<T,Dim...>> {
 	using MetaSchema = schema::Void;
-	using Schema = schema::FixedArray<T,Dim>;
+	using Schema = schema::FixedArray<T,Dim...>;
 };
 }
diff --git a/modules/codec/c++/simple.hpp b/modules/codec/c++/simple.hpp
index 33831b6..4990578 100644
--- a/modules/codec/c++/simple.hpp
+++ b/modules/codec/c++/simple.hpp
@@ -169,7 +169,7 @@ template<typename FromEnc>
 struct kelsimple_encode<schema::String, FromEnc> {
 	static error_or<void> encode(const data<schema::String, FromEnc>& from, buffer& to){
 		const auto str_size = from.size();
-		typename native_data_type<schema::UInt64>::type str_len = static_cast<uint64_t>(str_size);
+		typename native_data_type<schema::UInt64>::type str_len = static_cast<uint64_t>(str_size.get());
 		{
 			auto eov = stream_value<schema::UInt64>::encode(str_len, to);
 			if(eov.is_error()){
@@ -177,8 +177,8 @@ struct kelsimple_encode<schema::String, FromEnc> {
 			}
 		}
 
-		for(std::size_t i = 0; i < str_size; ++i){
-			auto eov = stream_value<schema::Int8>::encode(from.at(i), to);
+		for(data<schema::UInt64> i = 0; i < str_size; ++i){
+			auto eov = stream_value<schema::Int8>::encode(from.at(i.get()), to);
 			if(eov.is_error()){
 				return eov;
 			}
@@ -344,14 +344,14 @@ struct kelsimple_decode<schema::String, FromEnc> {
 			}
 			to = data<schema::String,FromEnc>{val};
 		}
-		const std::size_t str_size = to.size();
-		for(std::size_t i = 0; i < str_size; ++i){
+		const data<schema::UInt64> str_size = to.size();
+		for(data<schema::UInt64> i = 0; i < str_size; ++i){
 			int8_t val{};
 			auto eov = stream_value<schema::Int8>::decode(val, from);
 			if(eov.is_error()){
 				return eov;
 			}
-			to.set_at(i, val);
+			to.set_at(i.get(), val);
 		}
 		return void_t{};
 	}
diff --git a/modules/codec/examples/arg_parser.cpp b/modules/codec/examples/arg_parser.cpp
index 569c464..34a0b1d 100644
--- a/modules/codec/examples/arg_parser.cpp
+++ b/modules/codec/examples/arg_parser.cpp
@@ -40,7 +40,7 @@ int main(int argc, char** argv){
 	std::cout<<"=======\n";
 	std::cout<<"\nProgram: ";
 	auto& prog = nat_dat.template get<"program">();
-	for(uint64_t i = 0; i < prog.size(); ++i){
+	for(uint64_t i = 0; i < prog.size().get(); ++i){
 		std::cout<<prog.at(i);
 	}
 	std::cout<<"\n";
@@ -49,7 +49,7 @@ int main(int argc, char** argv){
 	{
 		std::cout<<"File: ";
 		auto& file_val = str_val.template get<"file">();
-		for(uint64_t i = 0; i < file_val.size(); ++i){
+		for(uint64_t i = 0; i < file_val.size().get(); ++i){
 			std::cout<<file_val.at(i);
 		}
 		std::cout<<"\n";
diff --git a/modules/codec/tests/codec.cpp b/modules/codec/tests/codec.cpp
index 7ad1c89..a1f37b8 100644
--- a/modules/codec/tests/codec.cpp
+++ b/modules/codec/tests/codec.cpp
@@ -58,13 +58,13 @@ SAW_TEST("One Dimensional Array") {
 
 	int bar = 0;
 
-	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
+	for(data<schema::UInt64, encode::Native> i = 0; i < arr.size(); ++i){
 		arr.at(i).set(bar++);
 	}
 
 	int sum = 0;
 	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
-		sum += arr.at(i).get();
+		sum += arr.at(data<schema::UInt64>{i}).get();
 	}
 
 	SAW_EXPECT(sum == 124750, std::to_string(sum) + " is not 124750. Expected that data stays correct");
@@ -76,7 +76,7 @@ SAW_TEST("One dim Array Default init"){
 	data<schema::OneDimArray, encode::Native> arr;
 
 	SAW_EXPECT(arr.get_dim_size(0) == 0, "Dim should be size 0");
-	SAW_EXPECT(arr.size() == 0, "Total size should also be zero");
+	SAW_EXPECT(arr.size().get() == 0u, "Total size should also be zero");
 }
 
 SAW_TEST("One dimensional Array Add"){
@@ -87,13 +87,13 @@ SAW_TEST("One dimensional Array Add"){
 	int bar = 0;
 
 	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
-		arr.at(i).set(bar++);
+		arr.at(data<schema::UInt64>{i}).set(bar++);
 	}
 
 	arr.add(7);
 
-	SAW_EXPECT(arr.size() == 6u, "Array size is not 6u. Expected that data stays correct");
-	SAW_EXPECT(arr.at(5u).get() == 7, "Array at 5u is not 7. Expected that data stays correct");
+	SAW_EXPECT(arr.size().get() == 6u, "Array size is not 6u. Expected that data stays correct");
+	SAW_EXPECT(arr.at(data<schema::UInt64>{5u}).get() == 7, "Array at 5u is not 7. Expected that data stays correct");
 }
 
 SAW_TEST("Two Dimensional Array") {
@@ -108,13 +108,13 @@ SAW_TEST("Two Dimensional Array") {
 	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
 		for(size_t j = 0; j < arr.get_dim_size(1); ++j){
 			++bar;
-			arr.at(i,j).set(bar);
+			arr.at({i,j}).set(bar);
 		}
 	}
 	int sum = 0;
 	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
 		for(size_t j = 0; j < arr.get_dim_size(1); ++j){
-			sum += arr.at(i,j).get();
+			sum += arr.at({i,j}).get();
 		}
 	}
 	SAW_EXPECT(sum == expected_sum, std::to_string(sum) + " is not "+ std::to_string(expected_sum) + ". Expected that data stays correct");
@@ -132,7 +132,7 @@ SAW_TEST("Three Dimensional Array") {
 		for(size_t j = 0; j < arr.get_dim_size(1); ++j){
 			for(size_t k = 0; k < arr.get_dim_size(2); ++k){
 				++bar;
-				arr.at(i,j,k).set(bar);
+				arr.at({i,j,k}).set(bar);
 			}
 		}
 	}
@@ -140,7 +140,7 @@ SAW_TEST("Three Dimensional Array") {
 	for(size_t i = 0; i < arr.get_dim_size(0); ++i){
 		for(size_t j = 0; j < arr.get_dim_size(1); ++j){
 			for(size_t k = 0; k < arr.get_dim_size(2); ++k){
-				sum += arr.at(i,j,k).get();
+				sum += arr.at({i,j,k}).get();
 			}
 		}
 	}
@@ -202,7 +202,7 @@ SAW_TEST("KelSimple Array write and read back"){
 
 	for(std::size_t i = 0; i < 2; ++i) {
 		for(std::size_t j = 0; j < 3; ++j){
-			native.at(i,j).set(i+2*j);
+			native.at({i,j}).set(i+2*j);
 		}
 	}
 
@@ -211,7 +211,7 @@ SAW_TEST("KelSimple Array write and read back"){
 	
 	for(std::size_t i = 0; i < 2; ++i) {
 		for(std::size_t j = 0; j < 3; ++j){
-			native.at(i,j).set(0);
+			native.at({i,j}).set(0);
 		}
 	}
 
@@ -220,7 +220,7 @@ SAW_TEST("KelSimple Array write and read back"){
 
 	for(std::size_t i = 0; i < 2; ++i) {
 		for(std::size_t j = 0; j < 3; ++j){
-			SAW_EXPECT(native.at(i,j).get() == static_cast<int32_t>(i+2*j), "Values incorrectly decoded");
+			SAW_EXPECT(native.at({i,j}).get() == static_cast<int32_t>(i+2*j), "Values incorrectly decoded");
 		}
 	}
 }
@@ -234,8 +234,8 @@ SAW_TEST("KelSimple Struct write and read back"){
 	auto& tda = native.template get<"two_dim_array">();
 	tda = {1,2};
 
-	tda.at(0,0).set(5);
-	tda.at(0,1).set(3);
+	tda.at({0,0}).set(5);
+	tda.at({0,1}).set(3);
 	native.template get<"number">().set(410);
 	
 	codec<schema::TestStruct, encode::KelSimple> codec;
@@ -251,8 +251,8 @@ SAW_TEST("KelSimple Struct write and read back"){
 
 	auto& dec_tda = native.template get<"two_dim_array">();
 
-	SAW_EXPECT(dec_tda.at(0,0).get() == 5, "Incorrect Decoding in array 0,0");
-	SAW_EXPECT(dec_tda.at(0,1).get() == 3, "Incorrect Decoding in array 0,1");
+	SAW_EXPECT(dec_tda.at({0,0}).get() == 5, "Incorrect Decoding in array 0,0");
+	SAW_EXPECT(dec_tda.at({0,1}).get() == 3, "Incorrect Decoding in array 0,1");
 	SAW_EXPECT(native.template get<"number">().get() == 410, "Incorrect Decoding in number");
 }
 
@@ -302,8 +302,8 @@ SAW_TEST("KelSimple Tuple write and read back"){
 	auto& tda = native.template get<0>();
 	tda = {1,2};
 
-	tda.at(0,0).set(5);
-	tda.at(0,1).set(3);
+	tda.at({0,0}).set(5);
+	tda.at({0,1}).set(3);
 	native.template get<1>().set(410);
 	
 	codec<schema::TestTuple, encode::KelSimple> codec;
@@ -319,8 +319,8 @@ SAW_TEST("KelSimple Tuple write and read back"){
 
 	auto& dec_tda = native.template get<0>();
 
-	SAW_EXPECT(dec_tda.at(0,0).get() == 5, "Incorrect Decoding in array 0,0");
-	SAW_EXPECT(dec_tda.at(0,1).get() == 3, "Incorrect Decoding in array 0,1");
+	SAW_EXPECT(dec_tda.at({0,0}).get() == 5, "Incorrect Decoding in array 0,0");
+	SAW_EXPECT(dec_tda.at({0,1}).get() == 3, "Incorrect Decoding in array 0,1");
 	SAW_EXPECT(native.template get<1>().get() == 410, "Incorrect Decoding in number");
 }
 
diff --git a/modules/codec/tests/csv.cpp b/modules/codec/tests/csv.cpp
index 417a547..5772e20 100644
--- a/modules/codec/tests/csv.cpp
+++ b/modules/codec/tests/csv.cpp
@@ -28,19 +28,19 @@ SAW_TEST("Codec Csv/Encode Basic"){
 	size_t n_size = 3u;
 	data <TestArray, encode::Native> native_data{n_size};
 	{
-		auto& row = native_data.at(0);
+		auto& row = native_data.at(data<schema::UInt64>{0});
 		row.template get<"string">().set("foo");
 		row.template get<"number">().set(140u);
 		row.template get<"signed">().set(1);
 	}
 	{
-		auto& row = native_data.at(1);
+		auto& row = native_data.at(data<schema::UInt64>{1});
 		row.template get<"string">().set("bar");
 		row.template get<"number">().set(245u);
 		row.template get<"signed">().set(2);
 	}
 	{
-		auto& row = native_data.at(2);
+		auto& row = native_data.at(data<schema::UInt64>{2});
 		row.template get<"string">().set("ban and anna");
 		row.template get<"number">().set(42u);
 		row.template get<"signed">().set(3);
diff --git a/modules/codec/tests/data.cpp b/modules/codec/tests/data.cpp
new file mode 100644
index 0000000..816aa1c
--- /dev/null
+++ b/modules/codec/tests/data.cpp
@@ -0,0 +1,32 @@
+#include <forstio/test/suite.hpp>
+#include "../c++/data.hpp"
+
+namespace {
+namespace sch {
+using namespace saw::schema;
+
+using Int32Array = Array<
+	Int32
+>;
+}
+
+SAW_TEST("Data Native/Array Access with Data Native"){
+	using namespace saw;
+
+	data<sch::Int32Array,encode::Native> prim{2u};
+	prim.at(1u).set(0);
+
+	data<schema::UInt64, encode::Native> i{1u};
+
+	auto& a = prim.at({i});
+
+	a.set(5);
+
+	auto b = prim.at({i});
+	b.set(10);
+	// Check if it's a reference being manipulated
+	SAW_EXPECT(a.get() == 5, "'a' has unexpected value.");
+	SAW_EXPECT(b.get() == 10, "'b' has unexpected value.");
+}
+
+}
diff --git a/modules/codec/tests/transport.cpp b/modules/codec/tests/transport.cpp
index 8c786e9..e0e105f 100644
--- a/modules/codec/tests/transport.cpp
+++ b/modules/codec/tests/transport.cpp
@@ -33,8 +33,8 @@ SAW_TEST("Transport FixedLen Struct write and slice"){
 		auto& tda = native.template get<"two_dim_array">();
 		tda = {1,2};
 
-		tda.at(0,0).set(5);
-		tda.at(0,1).set(3);
+		tda.at({0,0}).set(5);
+		tda.at({0,1}).set(3);
 		native.template get<"number">().set(410);
 	}
 	codec<schema::TestStruct, encode::KelSimple> codec;
@@ -67,8 +67,8 @@ SAW_TEST("Transport FixedLen Struct write and slice"){
 		auto& tda = native.template get<"two_dim_array">();
 		tda = {1,2};
 
-		tda.at(0,0).set(2);
-		tda.at(0,1).set(4);
+		tda.at({0,0}).set(2);
+		tda.at({0,1}).set(4);
 		native.template get<"number">().set(709);
 	}
 	{
@@ -118,8 +118,8 @@ SAW_TEST("Transport FixedLen Struct write and slice"){
 		{
 			auto& tda = native.template get<"two_dim_array">();
 
-			SAW_EXPECT(tda.at(0,0).get() == 5, "Decoded value (0,0) wrong.");
-			SAW_EXPECT(tda.at(0,1).get() == 3, "Decoded value (0,1) wrong.");
+			SAW_EXPECT(tda.at({0,0}).get() == 5, "Decoded value (0,0) wrong.");
+			SAW_EXPECT(tda.at({0,1}).get() == 3, "Decoded value (0,1) wrong.");
 			SAW_EXPECT(native.template get<"number">().get() == 410, "Decoded value number wrong.");
 		}
 	}
@@ -148,8 +148,8 @@ SAW_TEST("Transport FixedLen Struct write and slice"){
 		{
 			auto& tda = native.template get<"two_dim_array">();
 
-			SAW_EXPECT(tda.at(0,0).get() == 2, "Decoded value (0,0) wrong.");
-			SAW_EXPECT(tda.at(0,1).get() == 4, "Decoded value (0,1) wrong.");
+			SAW_EXPECT(tda.at({0,0}).get() == 2, "Decoded value (0,0) wrong.");
+			SAW_EXPECT(tda.at({0,1}).get() == 4, "Decoded value (0,1) wrong.");
 			SAW_EXPECT(native.template get<"number">().get() == 709, "Decoded value number wrong.");
 		}
 	}