Add unit tests for most of util.cpp

luprex/core/cpp/util.hpp

@@ -19,15 +19,17 @@ enum WorldType {
     WORLD_TYPE_MASTER,
 };
 
-using stringvec = std::vector<std::string>;
-using stringset = std::set<std::string>;
+using StringVec = std::vector<std::string>;
 using HashValue = std::pair<uint64_t, uint64_t>;
 using IdVector = std::vector<int64_t>;
 
-// Split a string into multiple strings
-stringvec split(const std::string &s, char sep);
+// Unions and sorts two ID vectors.
+IdVector sort_union_id_vectors(const IdVector &v1, const IdVector &v2);
 
-// String to lowercase/uppercase
+// Split a string into multiple strings
+StringVec split(const std::string &s, char sep);
+
+// String to lowercase/uppercase.  Ascii only, no unicode.
 std::string tolower(std::string input);
 std::string toupper(std::string input);
 
@@ -45,19 +47,18 @@ std::string ltrim(std::string s);
 std::string rtrim(std::string s);
 std::string trim(std::string s);
 
+// Calculate distance between two points
+double distance_squared(double x1, double y1, double x2, double y2);
+
 // Read a file as one big string.
 std::string get_file_contents(const std::string &path);
 
 // Read a file as a vector of lines.
-stringvec   get_file_lines(const std::string &path);
+StringVec   get_file_lines(const std::string &path);
 
 // Get a file's fingerprint - ie, size and modification time.
 std::string get_file_fingerprint(const std::string &path);
 
-// Calculate distance between two points
-double distance_squared(double x1, double y1, double x2, double y2);
-
-
 // An XYZ coordinate, general purpose.
 struct XYZ {
     float x, y, z;