Error C2664

ilikesupernoodles · May 18, 2020, 1:14am

Hi all,

I’ve followed this tutorial to update my Hello World-esque gain VST from using the now deprecated ScopedPointer to std::uniqe_ptr However, I’ve got a silly error that I can’t seem to figure out for my first big hurdle as a learner.

I’ve narrowed it down to the following line

    mGainValue =
    std::make_unique<AudioProcessorValueTreeState::SliderAttachment>
    (new AudioProcessorValueTreeState::SliderAttachment(p.getAPVTS(), "gain", mGainSlider));

The error is here

Severity Code Description Project File Line Suppression State
Error C2664 ‘juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment(const juce::AudioProcessorValueTreeState::SliderAttachment &)’: cannot convert argument 1 from ‘_Ty’ to ‘const juce::AudioProcessorValueTreeState::SliderAttachment &’ Hard Gainer_SharedCode C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\include\memory 2064

While I understand that there is a type mismatch, I don’t understand why I am receiving it or how to proceed. The guides I have seen do not have different code. So, please, if anyone could shed some light on how I’m being an idiot, I’d be most appreciative.

xenakios · May 18, 2020, 1:21am

make_unique calls new itself internally, so it’s not needed in the call itself :

mGainValue = std::make_unique<AudioProcessorValueTreeState::SliderAttachment> (p.getAPVTS(), "gain", mGainSlider);

ilikesupernoodles · May 20, 2020, 12:03am

Thanks for the reply. However, removing the new keyword hasn’t fixed the error. It has been five days now that I have been stuck with this error and I cannot see how to resolve it. Do you have any idea what may be causing this issue?

McMartin · May 20, 2020, 9:33am

@ilikesupernoodles we can’t help you without knowing more about your code. Which exact version of JUCE are you using? What is the type of mGainValue? Does p.getAPVTS() return an AudioProcessorValueTreeState& as expected?

The error that you shared in your first post is also incomplete. It mentions _Ty, but it doesn’t say what _Ty is.

ilikesupernoodles · May 20, 2020, 5:17pm

I’m using Juce 5.4.7.

The mGainValue created as so

std::unique_ptr<AudioProcessorValueTreeState::SliderAttachment> mGainValue;

and the getAPVTS method is from the attached tutorial. It returns the mAPVTS variable.

public: 
    AudioProcessorValueTreeState& getAPVTS() { return mAPVTS; };
private:   
     AudioProcessorValueTreeState mAPVTS;

I can assure you that was the complete error, copy/pasted straight from Visual Studio’s output.

I haven’t changed any code since removing the new keyword, but the errors that appear on a clean build are now different. C2280 and C2248. All I have done since is close Projucer/Visual Studio and reboot my workstation.

Severity	Code	Description	Project	File	Line	Suppression State
Error	C2280	'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment(const juce::AudioProcessorValueTreeState::SliderAttachment &)': attempting to reference a deleted function (compiling source file ..\..\Source\PluginEditor.cpp)	Hard Gainer_SharedCode	C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\include\memory	2064

and

Severity	Code	Description	Project	File	Line	Suppression State
Error	C2248	'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment': cannot access private member declared in class 'juce::AudioProcessorValueTreeState::SliderAttachment' (compiling source file ..\..\Source\PluginEditor.cpp)	Hard Gainer_SharedCode	C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\include\memory	2063

Double clicking either error takes me to this function inside a file called “Memory”

// FUNCTION TEMPLATE make_unique
template <class _Ty, class... _Types, enable_if_t<!is_array_v<_Ty>, int> = 0>
_NODISCARD unique_ptr<_Ty> make_unique(_Types&&... _Args) { // make a unique_ptr
    return unique_ptr<_Ty>(new _Ty(_STD forward<_Types>(_Args)...));
}

If there is any other information I can provide that will help, let me know.

McMartin · May 20, 2020, 7:18pm

What you copy-pasted comes from the “Error List” view of Visual Studio, which contains a single line per error/warning. In the “Output” view (after making sure that it reads Show output from: Build in the top-left corner), you usually have more details about the error/warning. Please provide errors/warnings with all details.

Could you please copy-paste your current version of the code that fails to compile? Maybe you didn’t apply @Xenakios’ suggestion properly.

ilikesupernoodles · May 20, 2020, 7:50pm

1>------ Build started: Project: Hard Gainer_SharedCode, Configuration: Debug x64 ------
1>PluginProcessor.cpp
1>PluginEditor.cpp
1>D:\Hard Gainer\Source\PluginProcessor.cpp(84,55): warning C4100: 'index': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(88,60): warning C4100: 'index': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(93,76): warning C4100: 'newName': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(93,55): warning C4100: 'index': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(98,70): warning C4100: 'samplesPerBlock': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(98,54): warning C4100: 'sampleRate': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(150,86): warning C4100: 'midiMessages': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(194,66): warning C4100: 'destData': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(201,75): warning C4100: 'sizeInBytes': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(201,65): warning C4100: 'data': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(225,115): warning C4100: 'property': unreferenced formal parameter
1>D:\Hard Gainer\Source\PluginProcessor.cpp(225,68): warning C4100: 'treeWhosePropertyHasChanged': unreferenced formal parameter
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\include\memory(2064,35): error C2280: 'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment(const juce::AudioProcessorValueTreeState::SliderAttachment &)': attempting to reference a deleted function (compiling source file ..\..\Source\PluginEditor.cpp)
1>D:\JUCE\modules\juce_audio_processors\utilities\juce_AudioProcessorValueTreeState.h(452): message : see declaration of 'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment' (compiling source file ..\..\Source\PluginEditor.cpp)
1>D:\JUCE\modules\juce_audio_processors\utilities\juce_AudioProcessorValueTreeState.h(452,9): message : 'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment(const juce::AudioProcessorValueTreeState::SliderAttachment &)': function was explicitly deleted (compiling source file ..\..\Source\PluginEditor.cpp)
1>D:\Hard Gainer\Source\PluginEditor.cpp(44): message : see reference to function template instantiation 'std::unique_ptr<juce::AudioProcessorValueTreeState::SliderAttachment,std::default_delete<juce::AudioProcessorValueTreeState::SliderAttachment>> std::make_unique<juce::AudioProcessorValueTreeState::SliderAttachment,juce::AudioProcessorValueTreeState::SliderAttachment,0>(juce::AudioProcessorValueTreeState::SliderAttachment &&)' being compiled
1>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\include\memory(2063,59): error C2248: 'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment': cannot access private member declared in class 'juce::AudioProcessorValueTreeState::SliderAttachment' (compiling source file ..\..\Source\PluginEditor.cpp)
1>D:\JUCE\modules\juce_audio_processors\utilities\juce_AudioProcessorValueTreeState.h(452): message : see declaration of 'juce::AudioProcessorValueTreeState::SliderAttachment::SliderAttachment' (compiling source file ..\..\Source\PluginEditor.cpp)
1>D:\JUCE\modules\juce_audio_processors\utilities\juce_AudioProcessorValueTreeState.h(441): message : see declaration of 'juce::AudioProcessorValueTreeState::SliderAttachment' (compiling source file ..\..\Source\PluginEditor.cpp)
1>Done building project "Hard Gainer_SharedCode.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ==========

ilikesupernoodles · May 20, 2020, 8:47pm

I forgot to post the line in question in the previous reply. This is it now.

mGainValue =
        std::make_unique<AudioProcessorValueTreeState::SliderAttachment>
        (p.getAPVTS(), "gain", mGainSlider);

xenakios · May 20, 2020, 9:28pm

And mGainValue is std::unique_ptr<AudioProcessorValueTreeState::SliderAttachment> ?

ilikesupernoodles · May 22, 2020, 1:02am

That’s right.

std::unique_ptr<AudioProcessorValueTreeState::SliderAttachment> mGainValue;

jamiepond · November 24, 2020, 1:38am

Did you find a solution to this? Just having the same issue and wondered if you could share your findings? Thanks in advance!

daniel · November 24, 2020, 12:53pm

There is a 99% chance it is not the same issue, so please put all your information here or preferrably in a new thread. You may use the questions asked here to compile your posting:

What do you want to achieve?
What does your code look like? The line of error plus context, i.e. declaration of the involved variables
What is the exact error message?

Good luck debugging

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