ofEventListeners with ofParameter in a lambda #8216
Description
Hey in the current nightly build, the following now has a linker (I think) error:
// in ofApp.h
ofEventListeners listeners;
ofParameter<int> paramTest;
// in ofApp::setup()
paramTest.set("paramTest", 0, 0, 10);
listeners.push(paramTest.newListener([this](const ofParameter<int>& p){
std::cout << "paramTest listener called" << std::endl;
}));
This was compiling in a nightly back from 9/30/24; the related forum thread is here: https://forum.openframeworks.cc/t/ofparameter-capture-in-lambda-with-ofeventlisteners/44170. dimitre thinks some template code (?) has changed in ofParameter.h between the two nightly builds.
Capturing an ofAbstractParameter for a listener with an ofParameterGroup still compiles OK:
listeners.push(group.parameterChangedE().newListener([this](ofAbstractParameter& p){
std::cout << "group listener called" << std::endl;
}));
I'm not sure this usage capturing an ofParameter<> in a lambda is important from a design point of view, particularly since it has to be captured as const. I've always written the lambdas this way to be able to get access to the ofParameter stuff inside if I need it, like its min/max, or name, etc., and as a habit. But it's probably redundant, since the listener is on a specific ofParameter anyway. The exception might be if they're in a vector.
So there may be good reasons why the nightly has changed and I'm open to capturing a fundamental type instead of the whole ofParameter<>.