FLTKのメニュー、snd/0だとsndを選んだ後に0を選ぶっていう二段構えの動作になるの…? https://www.fltk.org/doc-1.3/classFl__Input__Choice.html
AudioOutMap["snd/0"] = std::pair<std::string, std::string>("snd/0", "");
pAudioOutputChoice->add("snd\/0");
AudioInMap["snd/0"] = std::pair<std::string, std::string>("snd/0", "");
pAudioInputChoice->add("snd\/0");
AudioOutMap["snd/1"] = std::pair<std::string, std::string>("snd/1", "");
pAudioOutputChoice->add("snd\/1");
AudioInMap["snd/1"] = std::pair<std::string, std::string>("snd/1", "");
pAudioInputChoice->add("snd\/1");
AudioなんとかMapはアプリ内部の管理情報、->add()がFLTKへの指示だけど…/を\でエスケープしてもダメ。
あっるぇー?\でエスケープできるって話じゃないのーって、アレか。\/じゃなく\\/じゃないとダメってやつかなあ。
"The characters "&", "/", "\", and "_" are treated as special characters in the label string. The "&" character specifies that the following character is an accelerator and will be underlined. The "\" character is used to escape the next character in the string. Labels starting with the "_" character cause a divider to be placed after that menu item."
https://www.fltk.org/documentation.php/doc-1.1/Fl_Menu_.html