openFrameworks / ofParameters cast

ofApp.cpp

// casting ofParameters
float v = static_cast<ofParameter<float>&>(parameter);
ofParameter<float> prop = static_cast<ofParameter<float>&>(parameter);
ofParameter<float> prop = parameter.cast<float>();
//which internally does the static cast you are using now.

//https://forum.openframeworks.cc/t/ofparametergroup-best-practices/18752/8

//--

// static and multi class gui
//https://forum.openframeworks.cc/t/using-ofxgui-slider-values-outside-of-ofapp/21293/11
//NOTICE:
//If you use vector for MyClass like #1 example above, please make sure MyClass’s destructor won’t be called.
//This happen often for example when you push_back() new element to vector. When you add new element to your vector, it could be automatically change its memory size to prepare future addition. During this auto expansion process, destructor ofGui is called and lose callback pointer information. Resulting mouse event stop working. To avoid this, and makes really sure its pointer and memory is under your control always, one could use shared pointer like below
vector<shared_ptr<MyClass>> myClasses;
// emplace_back