[ox/model] Add support to SerStr for allocating string

deps/ox/src/ox/mc/read.cpp

@@ -83,11 +83,12 @@ Error MetalClawReader::field(const char*, SerStr val) {
 			auto [size, err] = mc::decodeInteger<StringLength>(&m_buff[m_buffIt], m_buffLen - m_buffIt, &bytesRead);
 			m_buffIt += bytesRead;
 			oxReturnError(err);
+			auto data = val.data(size + 1);
 			// read the string
 			if (val.cap() > -1 && static_cast<StringLength>(val.cap()) >= size) {
 				if (m_buffIt + size <= m_buffLen) {
-					ox_memcpy(val.data(), &m_buff[m_buffIt], size);
-					val.data()[size] = 0;
+					ox_memcpy(data, &m_buff[m_buffIt], size);
+					data[size] = 0;
 					m_buffIt += size;
 				} else {
 					return OxError(MC_BUFFENDED);
@@ -96,7 +97,10 @@ Error MetalClawReader::field(const char*, SerStr val) {
 				return OxError(MC_OUTBUFFENDED);
 			}
 		} else {
-			val.data()[0] = 0;
+			auto data = val.data();
+			if (data) {
+				data[0] = 0;
+			}
 		}
 	}
 	++m_field;

deps/ox/src/ox/mc/test/tests.cpp

@@ -36,7 +36,7 @@ struct TestStructNest {
 
 struct TestStruct {
 	static constexpr auto TypeName = "TestStruct";
-	static constexpr auto Fields = 15;
+	static constexpr auto Fields = 16;
 	bool Bool = false;
 	int32_t Int = 0;
 	int32_t Int1 = 0;
@@ -48,10 +48,16 @@ struct TestStruct {
 	int32_t Int7 = 0;
 	int32_t Int8 = 0;
 	TestUnion Union;
+	char *CString = nullptr;
 	ox::BString<32> String = "";
 	uint32_t List[4] = {0, 0, 0, 0};
 	TestStructNest EmptyStruct;
 	TestStructNest Struct;
+
+	~TestStruct() {
+		delete[] CString;
+	}
+
 };
 
 template<typename T>
@@ -86,6 +92,7 @@ ox::Error model(T *io, TestStruct *obj) {
 	oxReturnError(io->field("Int7", &obj->Int7));
 	oxReturnError(io->field("Int8", &obj->Int8));
 	oxReturnError(io->field("Union", ox::UnionView{&obj->Union, 1}));
+	oxReturnError(io->field("CString", ox::SerStr(&obj->CString)));
 	oxReturnError(io->field("String", &obj->String));
 	oxReturnError(io->field("List", obj->List, 4));
 	oxReturnError(io->field("EmptyStruct", &obj->EmptyStruct));
@@ -120,6 +127,8 @@ std::map<std::string, ox::Error(*)()> tests = {
 				testIn.Int = 42;
 				testIn.Union.Int = 42;
 				testIn.String = "Test String 1";
+				testIn.CString = new char[ox_strlen("c-string") + 1];
+				ox_strcpy(testIn.CString, "c-string");
 				testIn.List[0] = 1;
 				testIn.List[1] = 2;
 				testIn.List[2] = 3;
@@ -142,6 +151,7 @@ std::map<std::string, ox::Error(*)()> tests = {
 				oxAssert(testIn.Int6               == testOut.Int6, "Int6 value mismatch");
 				oxAssert(testIn.Int7               == testOut.Int7, "Int7 value mismatch");
 				oxAssert(testIn.Int8               == testOut.Int8, "Int8 value mismatch");
+				oxAssert(ox_strcmp(testIn.CString, testOut.CString) == 0, "CString value mismatch");
 				oxAssert(testIn.Union.Int          == testOut.Union.Int, "Union.Int value mismatch");
 				oxAssert(testIn.String             == testOut.String, "String value mismatch");
 				oxAssert(testIn.List[0]            == testOut.List[0], "List[0] value mismatch");

deps/ox/src/ox/mc/write.cpp

@@ -68,7 +68,7 @@ Error MetalClawWriter::field(const char*, bool *val) noexcept {
 
 Error MetalClawWriter::field(const char*, SerStr val) noexcept {
 	bool fieldSet = false;
-	if (val.cap() && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+	if (val.len() && (m_unionIdx == -1 || m_unionIdx == m_field)) {
 		// write the length
 		const auto strLen = mc::encodeInteger(val.len());
 		if (m_buffIt + strLen.length + val.len() < m_buffLen) {

deps/ox/src/ox/model/types.hpp

@@ -20,6 +20,7 @@ class SerStr {
 	protected:
 		int m_cap = 0;
 		char *m_str = nullptr;
+		char **m_tgt = nullptr;
 
 	public:
 		template<std::size_t sz>
@@ -33,6 +34,12 @@ class SerStr {
 			m_cap = cap;
 		}
 
+		constexpr SerStr(char **tgt, int cap = -1) noexcept {
+			m_tgt = tgt;
+			m_str = const_cast<char*>(*tgt);
+			m_cap = cap;
+		}
+
 		template<std::size_t cap>
 		constexpr SerStr(char (&str)[cap]) noexcept {
 			m_str = str;
@@ -43,13 +50,17 @@ class SerStr {
 			return m_str;
 		}
 
-		constexpr char *data() noexcept {
-			// do not return a non-const pointer to the const_casted m_str
+		constexpr char *data(std::size_t sz = 0) noexcept {
+			if (m_tgt && sz) {
+				*m_tgt = new char[sz];
+				m_str = *m_tgt;
+				m_cap = sz;
+			}
 			return m_str;
 		}
 
 		constexpr int len() noexcept {
-			return ox_strlen(m_str);
+			return m_str ? ox_strlen(m_str) : 0;
 		}
 
 		constexpr int cap() noexcept {

deps/ox/src/ox/std/strops.hpp

@@ -12,6 +12,18 @@
 #include "types.hpp"
 #include "typetraits.hpp"
 
+template<typename T1, typename T2>
+constexpr char *ox_strcpy(T1 dest, T2 src) noexcept {
+	std::size_t i = 0;
+	while (src[i]) {
+		dest[i] = src[i];
+		++i;
+	}
+	// set null terminator
+	dest[i] = 0;
+	return dest;
+}
+
 template<typename T1, typename T2>
 constexpr char *ox_strncpy(T1 dest, T2 src, std::size_t maxLen) noexcept {
 	std::size_t i = 0;