没有运算符“=”匹配这些操作数，JUCE window 演示应用程序

Question

当我尝试从 This tutorial 编译演示文件时，出现 no operator "=" matches these operands 错误。我试过包括字符串（来自类似问题的建议），但这似乎没有意义，因为它应该已经包含在 JuceHeader.h.

中

代码问题：

void initialise (const String& commandLine) override
{
    // Add your application's initialisation code here..

    mainWindow = new MainWindow (getApplicationName());
}

完整代码：

#include "../JuceLibraryCode/JuceHeader.h"
#include <string>


//==============================================================================
class MainWindowTutorialApplication  : public JUCEApplication
{
public:
    //==============================================================================
    MainWindowTutorialApplication() {}

    const String getApplicationName() override       { return ProjectInfo::projectName; }
    const String getApplicationVersion() override    { return ProjectInfo::versionString; }
    bool moreThanOneInstanceAllowed() override       { return true; }

    //==============================================================================
    void initialise (const String& commandLine) override
    {
        // Add your application's initialisation code here..

        mainWindow = new MainWindow (getApplicationName());
    }

    void shutdown() override
    {
        // Add your application's shutdown code here..
        mainWindow = nullptr;
    }

    //==============================================================================
    void systemRequestedQuit() override
    {
        // This is called when the app is being asked to quit: you can ignore this
        // request and let the app carry on running, or call quit() to allow the app to close.
        quit();
    }

    void anotherInstanceStarted (const String& commandLine) override
    {
        // When another instance of the app is launched while this one is running,
        // this method is invoked, and the commandLine parameter tells you what
        // the other instance's command-line arguments were.
    }

    class MainWindow : public DocumentWindow
    {
    public:
        MainWindow(String name) : DocumentWindow(name,
            Colours::lightgrey,
            DocumentWindow::allButtons)
        {
            centreWithSize(300, 200);
            setVisible(true);
        }

        void closeButtonPressed() override
        {
            JUCEApplication::getInstance()->systemRequestedQuit();
        }

    private:
        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(MainWindow)
    };

private:
    std::unique_ptr<MainWindow> mainWindow;
};

//==============================================================================
// This macro generates the main() routine that launches the app.
START_JUCE_APPLICATION (MainWindowTutorialApplication)

Answer 1

编译器告诉您不能将指针分配给 unique_ptr，这是真的：std::unique_ptr::operator=。您只能移动另一个 unique_ptr 或分配 nullptr。有两种可能的解决方案：

mainWindow.reset(new MainWindow(getApplicationName()));

或

mainWindow = std::make_unique<MainWindow>(getApplicationName());

没有运算符“=”匹配这些操作数，JUCE window 演示应用程序

no operator "=" matches these operands, JUCE window demo application

c++

juce