Attempting to reference a deleted function

General JUCE discussion
1

I have the following code in VS 2022:

#include <pybind11/pybind11.h>
#include <JuceHeader.h>

namespace py = pybind11;
using namespace std;
using namespace juce;

class ErrorLoadingPlugin : public std::exception 
{
public:
  char* what() 
  {
    return "Error: Could not load plugin.";
  }
};

class Plugin
{
  juce::AudioPluginFormatManager manager;
  std::unique_ptr< AudioPluginInstance > instance;
public:
  Plugin(string filepath, string formatname, int bitrate, int buffersize)
  {
    PluginDescription desc;
    desc.fileOrIdentifier = filepath;
    desc.pluginFormatName = formatname;
    juce::String errmsg;
    this->manager = juce::AudioPluginFormatManager();
    this->instance = manager.createPluginInstance(desc, bitrate, buffersize, errmsg);
    if (this->instance == nullptr)
    {
      throw ErrorLoadingPlugin();
    };
  };
};

PYBIND11_MODULE(PyMusic, m) 
{
  py::register_exception<ErrorLoadingPlugin>(module, "ErrorLoadingPlugin");
  py::class_<Plugin>(m, "Pet")
    .def(py::init<string, string, int, int>());
}

When I try to compile, I get the error “Attempting to reference a deleted function” in the line this->manager = juce::AudioPluginFormatManager();.
If I try to change it to

auto temp = juce::AudioPluginFormatManager();
this->manager = temp;

I get the same error but on the this->manager = temp line.

In another project I have the code:

#include <JuceHeader.h>
#include <iostream>
#include <pybind11/pybind11.h>
namespace py = pybind11;
using namespace std;

int main(int argc, char* argv[])
{
  juce::PluginDescription desc;
  desc.fileOrIdentifier = "D:\\soundshop\\vst\\Synth1V113beta3\\Synth1\\Synth1 VST64.dll";
  desc.pluginFormatName = "VST3";
  juce::String errmsg;
  juce::AudioPluginFormatManager manager = juce::AudioPluginFormatManager();
  auto instance = manager.createPluginInstance(desc, 44100, 512, errmsg);
  cout << errmsg;
  return 0;
}

And that compiles and runs just fine.

I have no idea how to get around this error.

2

In C++ this will try to copy assign a new juce::AudioPluginFormatManager. But the copy and assignment functions are disabled (deleted).

It is sufficient to have the manager as member, it will be created with the default constructor, no need to call it manually.

TL;DR: remove the line, it is not necessary

this->manager = juce::AudioPluginFormatManager();

And n.b. you don’t need to write this->, that is always implied.

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