unify stod/stoi invalid_argument::what parse

This is a hack to check whether given invalid_argument message belongs
to stoi/stod. It is usually used to catch non-numeric user input where
a number was expected.

src/hd-rum-translator/hd-rum-translator.cpp

@@ -1026,8 +1026,7 @@ int main(int argc, char **argv)
     try {
         ret = parse_fmt(argc, argv, &params);
     } catch (invalid_argument &e) {
-        if (strcmp(e.what(), "stoi") != 0 &&
-            strcmp(e.what(), "stod") != 0) {
+        if (!invalid_arg_is_numeric(e.what())) {
             throw;
         }
         MSG(ERROR, "Non-numeric value passed to option "

src/main.cpp

@@ -1013,8 +1013,7 @@ parse_options(int argc, char *argv[], struct ug_options *opt)
         try {
                 return parse_options_internal(argc, argv, opt);
         } catch (logic_error &e) {
-                if (strcmp(e.what(), "stoi") != 0 &&
-                    strcmp(e.what(), "stod") != 0) {
+                if (!invalid_arg_is_numeric(e.what())) {
                         throw;
                 }
                 if (dynamic_cast<invalid_argument *>(&e) != nullptr) {

src/utils/misc.cpp

@@ -329,3 +329,16 @@ bool is_arm_mac() {
         return false;
 #endif
 }
+
+/**
+ * @param what  value returned by std::logic_error::what()
+ * @returns if given std::invalid_argument message belongs to a stoi/stof
+ * converison
+ */
+
+bool invalid_arg_is_numeric(const char *what) {
+        if (what == nullptr) {
+                return false;
+        }
+        return strcmp(what, "stoi") == 0 || strcmp(what, "stod") == 0;
+}

src/utils/misc.h

@@ -71,6 +71,8 @@ struct key_val {
 };
 void print_module_usage(const char *module_name, const struct key_val *options, const struct key_val *options_full, bool print_full_help);
 
+bool invalid_arg_is_numeric(const char *what);
+
 #ifdef __cplusplus
 }
 #endif

src/video_display/decklink.cpp

@@ -1416,8 +1416,7 @@ static void *display_decklink_init(struct module *parent, const char *fmt, unsig
         try {
                 succeeded = settings_init(s, fmt, cardId);
         } catch (exception &e) {
-                if (strcmp(e.what(), "stoi") == 0 ||
-                    strcmp(e.what(), "stod") == 0) {
+                if (invalid_arg_is_numeric(e.what())) {
                         MSG(ERROR, "Invalid number passed where numeric "
                                    "argument expected!\n");
                 } else {