Make the string_value of mvt_value std::optional

evaluator.cpp

@@ -8,10 +8,10 @@
 #include "errors.hpp"
 #include "milo/dtoa_milo.h"
 
-static std::string mvt_value_to_string(mvt_value one, bool &fail) {
+static std::string mvt_value_to_string(mvt_value const &one, bool &fail) {
 	switch (one.type) {
 	case mvt_string:
-		return one.string_value;
+		return *(one.string_value);
 	case mvt_float:
 		return milo::dtoa_milo(one.numeric_value.float_value);
 	case mvt_double:
@@ -34,7 +34,7 @@ static std::string mvt_value_to_string(mvt_value one, bool &fail) {
 	}
 }
 
-int compare_fsl(mvt_value one, json_object *two, bool &fail) {
+int compare_fsl(mvt_value const &one, json_object *two, bool &fail) {
 	// In FSL expressions, the attribute value is coerced to the type
 	// of the JSON literal value it is being compared to.
 	//
@@ -53,7 +53,7 @@ int compare_fsl(mvt_value one, json_object *two, bool &fail) {
 		switch (one.type) {
 		case mvt_string: {
 			char *endptr = NULL;
-			const char *s = one.string_value.c_str();
+			const char *s = one.string_value->c_str();
 			lhs = strtod(s, &endptr);
 			if (endptr == s) {
 				fail = true;  // non-numeric-string op number => null
@@ -106,7 +106,7 @@ int compare_fsl(mvt_value one, json_object *two, bool &fail) {
 
 		switch (one.type) {
 		case mvt_string:
-			lhs = one.string_value.size() > 0;
+			lhs = one.string_value->size() > 0;
 			break;
 		case mvt_float:
 			lhs = one.numeric_value.float_value != 0;
@@ -144,7 +144,7 @@ int compare_fsl(mvt_value one, json_object *two, bool &fail) {
 	exit(EXIT_IMPOSSIBLE);
 }
 
-int compare(mvt_value one, json_object *two, bool &fail) {
+int compare(mvt_value const &one, json_object *two, bool &fail) {
 	switch (one.type) {
 	case mvt_string:
 		if (two->type != JSON_STRING) {
@@ -152,7 +152,7 @@ int compare(mvt_value one, json_object *two, bool &fail) {
 			return false;  // string vs non-string
 		}
 
-		return strcmp(one.string_value.c_str(), two->value.string.string);
+		return strcmp(one.string_value->c_str(), two->value.string.string);
 
 	case mvt_double:
 	case mvt_float:

mvt.cpp

@@ -329,7 +329,7 @@ std::string mvt_tile::encode() {
 
 			switch (pbv.type) {
 			case mvt_string:
-				value_writer.add_string(1, pbv.string_value);
+				value_writer.add_string(1, *(pbv.string_value));
 				break;
 			case mvt_float:
 				value_writer.add_float(2, pbv.numeric_value.float_value);
@@ -458,7 +458,7 @@ bool mvt_value::operator<(const mvt_value &o) const {
 	if (type == o.type) {
 		switch (type) {
 		case mvt_string:
-			return string_value < o.string_value;
+			return *string_value < *(o.string_value);
 
 		case mvt_float:
 			return numeric_value.float_value < o.numeric_value.float_value;
@@ -494,7 +494,7 @@ bool mvt_value::operator==(const mvt_value &o) const {
 	if (type == o.type) {
 		switch (type) {
 		case mvt_string:
-			return string_value == o.string_value;
+			return *string_value == *(o.string_value);
 
 		case mvt_float:
 			return numeric_value.float_value == o.numeric_value.float_value;
@@ -550,7 +550,7 @@ static std::string quote(std::string const &s) {
 std::string mvt_value::toString() const {
 	switch (type) {
 	case mvt_string:
-		return quote(string_value);
+		return quote(*string_value);
 	case mvt_int:
 		return std::to_string(numeric_value.int_value);
 	case mvt_double: {
@@ -767,7 +767,7 @@ serial_val mvt_value_to_serial_val(mvt_value const &v) {
 	switch (v.type) {
 	case mvt_string:
 		sv.type = mvt_string;
-		sv.s = v.string_value;
+		sv.s = *(v.string_value);
 		break;
 	case mvt_float:
 		sv.type = mvt_double;
@@ -809,7 +809,7 @@ serial_val mvt_value_to_serial_val(mvt_value const &v) {
 long long mvt_value_to_long_long(mvt_value const &v) {
 	switch (v.type) {
 	case mvt_string:
-		return atoll(v.string_value.c_str());
+		return atoll(v.string_value->c_str());
 	case mvt_float:
 		return v.numeric_value.float_value;
 	case mvt_double:

mvt.hpp

@@ -6,6 +6,7 @@
 #include <unordered_map>
 #include <set>
 #include <vector>
+#include <optional>
 
 #include "errors.hpp"
 
@@ -74,7 +75,7 @@ enum mvt_value_type {
 
 struct mvt_value {
 	mvt_value_type type;
-	std::string string_value;
+	std::optional<std::string> string_value;
 	union {
 		float float_value;
 		double double_value;
@@ -104,7 +105,7 @@ struct std::hash<mvt_value> {
 
 		switch (k.type) {
 		case mvt_string:
-			return std::hash<string>()(k.string_value);
+			return std::hash<string>()(*(k.string_value));
 
 		case mvt_float:
 			return std::hash<float>()(k.numeric_value.float_value);

tile.cpp

@@ -217,7 +217,7 @@ void decode_meta(std::vector<long long> const &metakeys, std::vector<long long>
 		mvt_value key = retrieve_string(metakeys[i], stringpool, NULL);
 		mvt_value value = retrieve_string(metavals[i], stringpool, &otype);
 
-		layer.tag(feature, key.string_value, value);
+		layer.tag(feature, *(key.string_value), value);
 	}
 }
 
@@ -227,9 +227,9 @@ static int metacmp(const std::vector<long long> &keys1, const std::vector<long l
 		mvt_value key1 = retrieve_string(keys1[i], stringpool1, NULL);
 		mvt_value key2 = retrieve_string(keys2[i], stringpool2, NULL);
 
-		if (key1.string_value < key2.string_value) {
+		if (*(key1.string_value) < *(key2.string_value)) {
 			return -1;
-		} else if (key1.string_value > key2.string_value) {
+		} else if (*(key1.string_value) > *(key2.string_value)) {
 			return 1;
 		}
 
@@ -273,7 +273,7 @@ static mvt_value find_attribute_value(const struct coalesce *c1, std::string key
 
 	for (size_t i = 0; i < keys1.size(); i++) {
 		mvt_value key1 = retrieve_string(keys1[i], stringpool1, NULL);
-		if (key == key1.string_value) {
+		if (key == *(key1.string_value)) {
 			return retrieve_string(values1[i], stringpool1, NULL);
 		}
 	}

write_json.cpp

@@ -339,7 +339,7 @@ void layer_to_geojson(mvt_layer const &layer, unsigned z, unsigned x, unsigned y
 			switch (val.type) {
 			case mvt_string:
 				state.json_write_string(key);
-				state.json_write_string(val.string_value);
+				state.json_write_string(*(val.string_value));
 				break;
 			case mvt_int:
 				state.json_write_string(key);