Add support for save/loading std::strings.

src/string_func.h

@@ -27,6 +27,7 @@
 #define STRING_FUNC_H
 
 #include <stdarg.h>
+#include <string>
 
 #include "core/bitmath_func.hpp"
 #include "string_type.h"
@@ -41,7 +42,27 @@ int CDECL vseprintf(char *str, const char *last, const char *format, va_list ap)
 char *CDECL str_fmt(const char *str, ...) WARN_FORMAT(1, 2);
 char *str_vfmt(const char *str, va_list ap);
 
-void str_validate(char *str, const char *last, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK);
+char *str_validate_intl(char *str, const char *last, StringValidationSettings settings);
+
+/**
+ * Scans the string for valid characters and if it finds invalid ones,
+ * replaces them with a question mark '?' (if not ignored)
+ * @param str the string to validate
+ * @param last the last valid character of str
+ * @param settings the settings for the string validation.
+ */
+static inline void str_validate(char *str, const char *last, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK)
+{
+	*str_validate_intl(str, last, settings) = '\0';
+}
+
+static inline void str_validate(std::string &str, StringValidationSettings settings = SVS_REPLACE_WITH_QUESTION_MARK)
+{
+	if (str.empty()) return;
+	char *buf = const_cast<char *>(str.c_str());
+	str.resize(str_validate_intl(buf, buf + str.size(), settings) - buf);
+}
+
 void ValidateString(const char *str);
 
 void str_fix_scc_encoded(char *str, const char *last);