Copy routines for non-byte arrays.

libsolidity/ArrayUtils.cpp

@@ -231,6 +231,181 @@ void ArrayUtils::copyArrayToStorage(ArrayType const& _targetType, ArrayType cons
 	m_context << u256(0);
 }
 
+void ArrayUtils::copyArrayToMemory(const ArrayType& _sourceType, bool _padToWordBoundaries) const
+{
+	solAssert(
+		_sourceType.getBaseType()->getCalldataEncodedSize() > 0,
+		"Nested arrays not yet implemented here."
+	);
+	unsigned baseSize = 1;
+	if (!_sourceType.isByteArray())
+		// We always pad the elements, regardless of _padToWordBoundaries.
+		baseSize = _sourceType.getBaseType()->getCalldataEncodedSize();
+
+	if (_sourceType.location() == DataLocation::CallData)
+	{
+		if (!_sourceType.isDynamicallySized())
+			m_context << _sourceType.getLength();
+		if (_sourceType.getBaseType()->getCalldataEncodedSize() > 1)
+			m_context << u256(baseSize) << eth::Instruction::MUL;
+		// stack: target source_offset source_len
+		m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3 << eth::Instruction::DUP5;
+		// stack: target source_offset source_len source_len source_offset target
+		m_context << eth::Instruction::CALLDATACOPY;
+		m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
+		m_context << eth::Instruction::SWAP2 << eth::Instruction::POP << eth::Instruction::POP;
+	}
+	else if (_sourceType.location() == DataLocation::Memory)
+	{
+		// memcpy using the built-in contract
+		retrieveLength(_sourceType);
+		if (_sourceType.isDynamicallySized())
+		{
+			// change pointer to data part
+			m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
+			m_context << eth::Instruction::SWAP1;
+		}
+		// convert length to size
+		if (baseSize > 1)
+			m_context << u256(baseSize) << eth::Instruction::MUL;
+		// stack: <target> <source> <size>
+		//@TODO do not use ::CALL if less than 32 bytes?
+		m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::DUP4;
+		CompilerUtils(m_context).memoryCopy();
+
+		m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
+		// stack: <target> <size>
+
+		bool paddingNeeded = false;
+		if (_sourceType.isDynamicallySized())
+			paddingNeeded = _padToWordBoundaries && ((baseSize % 32) != 0);
+		else
+			paddingNeeded = _padToWordBoundaries && (((_sourceType.getLength() * baseSize) % 32) != 0);
+		if (paddingNeeded)
+		{
+			// stack: <target> <size>
+			m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2 << eth::Instruction::ADD;
+			// stack: <length> <target + size>
+			m_context << eth::Instruction::SWAP1 << u256(31) << eth::Instruction::AND;
+			// stack: <target + size> <remainder = size % 32>
+			eth::AssemblyItem skip = m_context.newTag();
+			if (_sourceType.isDynamicallySized())
+			{
+				m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
+				m_context.appendConditionalJumpTo(skip);
+			}
+			// round off, load from there.
+			// stack <target + size> <remainder = size % 32>
+			m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3;
+			m_context << eth::Instruction::SUB;
+			// stack: target+size remainder <target + size - remainder>
+			m_context << eth::Instruction::DUP1 << eth::Instruction::MLOAD;
+			// Now we AND it with ~(2**(8 * (32 - remainder)) - 1)
+			m_context << u256(1);
+			m_context << eth::Instruction::DUP4 << u256(32) << eth::Instruction::SUB;
+			// stack: ...<v> 1 <32 - remainder>
+			m_context << u256(0x100) << eth::Instruction::EXP << eth::Instruction::SUB;
+			m_context << eth::Instruction::NOT << eth::Instruction::AND;
+			// stack: target+size remainder target+size-remainder <v & ...>
+			m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
+			// stack: target+size remainder target+size-remainder
+			m_context << u256(32) << eth::Instruction::ADD;
+			// stack: target+size remainder <new_padded_end>
+			m_context << eth::Instruction::SWAP2 << eth::Instruction::POP;
+
+			if (_sourceType.isDynamicallySized())
+				m_context << skip.tag();
+			// stack <target + "size"> <remainder = size % 32>
+			m_context << eth::Instruction::POP;
+		}
+		else
+			// stack: <target> <size>
+			m_context << eth::Instruction::ADD;
+	}
+	else
+	{
+		solAssert(_sourceType.location() == DataLocation::Storage, "");
+		unsigned storageBytes = _sourceType.getBaseType()->getStorageBytes();
+		u256 storageSize = _sourceType.getBaseType()->getStorageSize();
+		solAssert(storageSize > 1 || (storageSize == 1 && storageBytes > 0), "");
+
+		m_context << eth::Instruction::POP; // remove offset, arrays always start new slot
+		retrieveLength(_sourceType);
+		// stack here: memory_offset storage_offset length
+		// jump to end if length is zero
+		m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
+		eth::AssemblyItem loopEnd = m_context.newTag();
+		m_context.appendConditionalJumpTo(loopEnd);
+		// compute memory end offset
+		if (baseSize > 1)
+			// convert length to memory size
+			m_context << u256(baseSize) << eth::Instruction::MUL;
+		m_context << eth::Instruction::DUP3 << eth::Instruction::ADD << eth::Instruction::SWAP2;
+		if (_sourceType.isDynamicallySized())
+		{
+			// actual array data is stored at SHA3(storage_offset)
+			m_context << eth::Instruction::SWAP1;
+			CompilerUtils(m_context).computeHashStatic();
+			m_context << eth::Instruction::SWAP1;
+		}
+
+		// stack here: memory_end_offset storage_data_offset memory_offset
+		bool haveByteOffset = !_sourceType.isByteArray() && storageBytes <= 16;
+		if (haveByteOffset)
+			m_context << u256(0) << eth::Instruction::SWAP1;
+		// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
+		eth::AssemblyItem loopStart = m_context.newTag();
+		m_context << loopStart;
+		// load and store
+		if (_sourceType.isByteArray())
+		{
+			// Packed both in storage and memory.
+			m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+			m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
+			// increment storage_data_offset by 1
+			m_context << eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD;
+			// increment memory offset by 32
+			m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
+		}
+		else
+		{
+			// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
+			if (haveByteOffset)
+				m_context << eth::Instruction::DUP3 << eth::Instruction::DUP3;
+			else
+				m_context << eth::Instruction::DUP2 << u256(0);
+			StorageItem(m_context, *_sourceType.getBaseType()).retrieveValue(SourceLocation(), true);
+			CompilerUtils(m_context).storeInMemoryDynamic(*_sourceType.getBaseType());
+			// increment storage_data_offset and byte offset
+			if (haveByteOffset)
+				incrementByteOffset(storageBytes, 2, 3);
+			else
+			{
+				m_context << eth::Instruction::SWAP1;
+				m_context << storageSize << eth::Instruction::ADD;
+				m_context << eth::Instruction::SWAP1;
+			}
+		}
+		// check for loop condition
+		m_context << eth::Instruction::DUP1 << eth::dupInstruction(haveByteOffset ? 5 : 4) << eth::Instruction::GT;
+		m_context.appendConditionalJumpTo(loopStart);
+		// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
+		if (haveByteOffset)
+			m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
+		if (_padToWordBoundaries && baseSize % 32 != 0)
+		{
+			// memory_end_offset - start is the actual length (we want to compute the ceil of).
+			// memory_offset - start is its next multiple of 32, but it might be off by 32.
+			// so we compute: memory_end_offset += (memory_offset - memory_end_offest) & 31
+			m_context << eth::Instruction::DUP3 << eth::Instruction::SWAP1 << eth::Instruction::SUB;
+			m_context << u256(31) << eth::Instruction::AND;
+			m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
+			m_context << eth::Instruction::SWAP2;
+		}
+		m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
+	}
+}
+
 void ArrayUtils::clearArray(ArrayType const& _type) const
 {
 	unsigned stackHeightStart = m_context.getStackHeight();

libsolidity/ArrayUtils.h

@@ -44,6 +44,10 @@ public:
 	/// Stack pre: source_reference [source_byte_offset/source_length] target_reference target_byte_offset
 	/// Stack post: target_reference target_byte_offset
 	void copyArrayToStorage(ArrayType const& _targetType, ArrayType const& _sourceType) const;
+	/// Copies an array (which cannot be dynamically nested) from anywhere to memory.
+	/// Stack pre: memory_offset source_item
+	/// Stack post: memory_offest + length(padded)
+	void copyArrayToMemory(ArrayType const& _sourceType, bool _padToWordBoundaries = true) const;
 	/// Clears the given dynamic or static array.
 	/// Stack pre: storage_ref storage_byte_offset
 	/// Stack post:

libsolidity/CompilerUtils.cpp

@@ -25,6 +25,7 @@
 #include <libevmcore/Instruction.h>
 #include <libevmcore/Params.h>
 #include <libsolidity/ArrayUtils.h>
+#include <libsolidity/LValue.h>
 
 using namespace std;
 
@@ -103,130 +104,10 @@ unsigned CompilerUtils::storeInMemory(unsigned _offset, Type const& _type, bool
 void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries)
 {
 	if (_type.getCategory() == Type::Category::Array)
-	{
+		ArrayUtils(m_context).copyArrayToMemory(
-		auto const& type = dynamic_cast<ArrayType const&>(_type);
+			dynamic_cast<ArrayType const&>(_type),
-		solAssert(type.isByteArray(), "Non byte arrays not yet implemented here.");
+			_padToWordBoundaries
-
+		);
-		if (type.location() == DataLocation::CallData)
-		{
-			if (!type.isDynamicallySized())
-				m_context << type.getLength();
-			// stack: target source_offset source_len
-			m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3 << eth::Instruction::DUP5;
-			// stack: target source_offset source_len source_len source_offset target
-			m_context << eth::Instruction::CALLDATACOPY;
-			m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
-			m_context << eth::Instruction::SWAP2 << eth::Instruction::POP << eth::Instruction::POP;
-		}
-		else if (type.location() == DataLocation::Memory)
-		{
-			// memcpy using the built-in contract
-			ArrayUtils(m_context).retrieveLength(type);
-			if (type.isDynamicallySized())
-			{
-				// change pointer to data part
-				m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
-				m_context << eth::Instruction::SWAP1;
-			}
-			// stack: <target> <source> <length>
-			// stack for call: outsize target size source value contract gas
-			m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4;
-			m_context << eth::Instruction::DUP2 << eth::Instruction::DUP5;
-			m_context << u256(0) << u256(identityContractAddress);
-			//@TODO do not use ::CALL if less than 32 bytes?
-			//@todo in production, we should not have to pair c_callNewAccountGas.
-			m_context << u256(eth::c_callGas + 15 + eth::c_callNewAccountGas) << eth::Instruction::GAS;
-			m_context << eth::Instruction::SUB << eth::Instruction::CALL;
-			m_context << eth::Instruction::POP; // ignore return value
-
-			m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
-			// stack: <target> <length>
-
-			if (_padToWordBoundaries && (type.isDynamicallySized() || (type.getLength()) % 32 != 0))
-			{
-				// stack: <target> <length>
-				m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2 << eth::Instruction::ADD;
-				// stack: <length> <target + length>
-				m_context << eth::Instruction::SWAP1 << u256(31) << eth::Instruction::AND;
-				// stack: <target + length> <remainder = length % 32>
-				eth::AssemblyItem skip = m_context.newTag();
-				if (type.isDynamicallySized())
-				{
-					m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
-					m_context.appendConditionalJumpTo(skip);
-				}
-				// round off, load from there.
-				// stack <target + length> <remainder = length % 32>
-				m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3;
-				m_context << eth::Instruction::SUB;
-				// stack: target+length remainder <target + length - remainder>
-				m_context << eth::Instruction::DUP1 << eth::Instruction::MLOAD;
-				// Now we AND it with ~(2**(8 * (32 - remainder)) - 1)
-				m_context << u256(1);
-				m_context << eth::Instruction::DUP4 << u256(32) << eth::Instruction::SUB;
-				// stack: ...<v> 1 <32 - remainder>
-				m_context << u256(0x100) << eth::Instruction::EXP << eth::Instruction::SUB;
-				m_context << eth::Instruction::NOT << eth::Instruction::AND;
-				// stack: target+length remainder target+length-remainder <v & ...>
-				m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
-				// stack: target+length remainder target+length-remainder
-				m_context << u256(32) << eth::Instruction::ADD;
-				// stack: target+length remainder <new_padded_end>
-				m_context << eth::Instruction::SWAP2 << eth::Instruction::POP;
-
-				if (type.isDynamicallySized())
-					m_context << skip.tag();
-				// stack <target + "length"> <remainder = length % 32>
-				m_context << eth::Instruction::POP;
-			}
-			else
-				// stack: <target> <length>
-				m_context << eth::Instruction::ADD;
-		}
-		else
-		{
-			solAssert(type.location() == DataLocation::Storage, "");
-			m_context << eth::Instruction::POP; // remove offset, arrays always start new slot
-			m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD;
-			// stack here: memory_offset storage_offset length_bytes
-			// jump to end if length is zero
-			m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
-			eth::AssemblyItem loopEnd = m_context.newTag();
-			m_context.appendConditionalJumpTo(loopEnd);
-			// compute memory end offset
-			m_context << eth::Instruction::DUP3 << eth::Instruction::ADD << eth::Instruction::SWAP2;
-			// actual array data is stored at SHA3(storage_offset)
-			m_context << eth::Instruction::SWAP1;
-			CompilerUtils(m_context).computeHashStatic();
-			m_context << eth::Instruction::SWAP1;
-
-			// stack here: memory_end_offset storage_data_offset memory_offset
-			eth::AssemblyItem loopStart = m_context.newTag();
-			m_context << loopStart;
-			// load and store
-			m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
-			m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
-			// increment storage_data_offset by 1
-			m_context << eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD;
-			// increment memory offset by 32
-			m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
-			// check for loop condition
-			m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::GT;
-			m_context.appendConditionalJumpTo(loopStart);
-			// stack here: memory_end_offset storage_data_offset memory_offset
-			if (_padToWordBoundaries)
-			{
-				// memory_end_offset - start is the actual length (we want to compute the ceil of).
-				// memory_offset - start is its next multiple of 32, but it might be off by 32.
-				// so we compute: memory_end_offset += (memory_offset - memory_end_offest) & 31
-				m_context << eth::Instruction::DUP3 << eth::Instruction::SWAP1 << eth::Instruction::SUB;
-				m_context << u256(31) << eth::Instruction::AND;
-				m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
-				m_context << eth::Instruction::SWAP2;
-			}
-			m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
-		}
-	}
 	else
 	{
 		unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries);
@@ -341,6 +222,21 @@ void CompilerUtils::encodeToMemory(
 	popStackSlots(argSize + dynPointers + 1);
 }
 
+void CompilerUtils::memoryCopy()
+{
+	// Stack here: size target source
+	// stack for call: outsize target size source value contract gas
+	//@TODO do not use ::CALL if less than 32 bytes?
+	m_context << eth::Instruction::DUP3 << eth::Instruction::SWAP1;
+	m_context << u256(0) << u256(identityContractAddress);
+	// compute gas costs
+	m_context << u256(32) << eth::Instruction::DUP5 << u256(31) << eth::Instruction::ADD;
+	m_context << eth::Instruction::DIV << u256(eth::c_identityWordGas) << eth::Instruction::MUL;
+	m_context << u256(eth::c_identityGas) << eth::Instruction::ADD;
+	m_context << eth::Instruction::CALL;
+	m_context << eth::Instruction::POP; // ignore return value
+}
+
 void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded)
 {
 	// For a type extension, we need to remove all higher-order bits that we might have ignored in

libsolidity/CompilerUtils.h

@@ -77,6 +77,8 @@ public:
 	);
 	/// Dynamic version of @see storeInMemory, expects the memory offset below the value on the stack
 	/// and also updates that. For arrays, only copies the data part.
+	/// @param _padToWordBoundaries if true, adds zeros to pad to multiple of 32 bytes. Array elements
+	/// are always padded (except for byte arrays), regardless of this parameter.
 	/// Stack pre: memory_offset value...
 	/// Stack post: (memory_offset+length)
 	void storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries = true);
@@ -99,6 +101,11 @@ public:
 		bool _copyDynamicDataInPlace = false
 	);
 
+	/// Uses a CALL to the identity contract to perform a memory-to-memory copy.
+	/// Stack pre: <size> <target> <source>
+	/// Stack post:
+	void memoryCopy();
+
 	/// Appends code for an implicit or explicit type conversion. This includes erasing higher
 	/// order bits (@see appendHighBitCleanup) when widening integer but also copy to memory
 	/// if a reference type is converted from calldata or storage to memory.

libsolidity/Types.cpp

@@ -721,9 +721,13 @@ bool ArrayType::isImplicitlyConvertibleTo(const Type& _convertTo) const
 	}
 	else
 	{
-		// Require that the base type is the same, not only convertible.
+		// Conversion to storage pointer or to memory, we de not copy element-for-element here, so
-		// This disallows assignment of nested arrays from storage to memory for now.
+		// require that the base type is the same, not only convertible.
-		if (*getBaseType() != *convertTo.getBaseType())
+		// This disallows assignment of nested dynamic arrays from storage to memory for now.
+		if (
+			*copyForLocationIfReference(location(), getBaseType()) !=
+			*copyForLocationIfReference(location(), convertTo.getBaseType())
+		)
 			return false;
 		if (isDynamicallySized() != convertTo.isDynamicallySized())
 			return false;

test/libsolidity/SolidityEndToEndTest.cpp

@@ -4517,6 +4517,105 @@ BOOST_AUTO_TEST_CASE(bytes_in_constructors_packer)
 	);
 }
 
+BOOST_AUTO_TEST_CASE(arrays_from_and_to_storage)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			uint24[] public data;
+			function set(uint24[] _data) returns (uint) {
+				data = _data;
+				return data.length;
+			}
+			function get() returns (uint24[]) {
+				return data;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+
+	vector<u256> data{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18};
+	BOOST_REQUIRE(
+		callContractFunction("set(uint24[])", u256(0x20), u256(data.size()), data) ==
+		encodeArgs(u256(data.size()))
+	);
+	BOOST_CHECK(callContractFunction("data(uint256)", u256(7)) == encodeArgs(u256(8)));
+	BOOST_CHECK(callContractFunction("data(uint256)", u256(15)) == encodeArgs(u256(16)));
+	BOOST_CHECK(callContractFunction("data(uint256)", u256(18)) == encodeArgs());
+	BOOST_CHECK(callContractFunction("get()") == encodeArgs(u256(0x20), u256(data.size()), data));
+}
+
+BOOST_AUTO_TEST_CASE(arrays_complex_from_and_to_storage)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			uint24[3][] public data;
+			function set(uint24[3][] _data) returns (uint) {
+				data = _data;
+				return data.length;
+			}
+			function get() returns (uint24[3][]) {
+				return data;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+
+	vector<u256> data{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18};
+	BOOST_REQUIRE(
+		callContractFunction("set(uint24[3][])", u256(0x20), u256(data.size() / 3), data) ==
+		encodeArgs(u256(data.size() / 3))
+	);
+	BOOST_CHECK(callContractFunction("data(uint256,uint256)", u256(2), u256(2)) == encodeArgs(u256(9)));
+	BOOST_CHECK(callContractFunction("data(uint256,uint256)", u256(5), u256(1)) == encodeArgs(u256(17)));
+	BOOST_CHECK(callContractFunction("data(uint256,uint256)", u256(6), u256(0)) == encodeArgs());
+	BOOST_CHECK(callContractFunction("get()") == encodeArgs(u256(0x20), u256(data.size() / 3), data));
+}
+
+BOOST_AUTO_TEST_CASE(arrays_complex_memory_index_access)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			function set(uint24[3][] _data, uint a, uint b) returns (uint l, uint e) {
+				l = _data.length;
+				e = _data[a][b];
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+
+	vector<u256> data{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18};
+	BOOST_REQUIRE(callContractFunction(
+			"set(uint24[3][],uint256,uint256)",
+			u256(0x60),
+			u256(3),
+			u256(2),
+			u256(data.size() / 3),
+			data
+	) == encodeArgs(u256(data.size() / 3), u256(data[3 * 3 + 2])));
+}
+
+BOOST_AUTO_TEST_CASE(bytes_memory_index_access)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			function set(bytes _data, uint i) returns (uint l, byte c) {
+				l = _data.length;
+				c = _data[i];
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+
+	string data("abcdefgh");
+	BOOST_REQUIRE(callContractFunction(
+			"set(bytes,uint256)",
+			u256(0x40),
+			u256(3),
+			u256(data.size()),
+			data
+	) == encodeArgs(u256(data.size()), string("d")));
+}
+
 BOOST_AUTO_TEST_CASE(storage_array_ref)
 {
 	char const* sourceCode = R"(

test/libsolidity/solidityExecutionFramework.h

@@ -127,6 +127,14 @@ public:
 		return _padLeft ? padding + _value : _value + padding;
 	}
 	static bytes encode(std::string const& _value) { return encode(asBytes(_value), false); }
+	template <class _T>
+	static bytes encode(std::vector<_T> const& _value)
+	{
+		bytes ret;
+		for (auto const& v: _value)
+			ret += encode(v);
+		return ret;
+	}
 
 	template <class FirstArg, class... Args>
 	static bytes encodeArgs(FirstArg const& _firstArg, Args const&... _followingArgs)