Returning struct from class method

lukutis222

Hello. In my application I want to return 3 values from a class method. For that, I have decided to create a struct (final_average_s) that contains the 3 values that I want to return.

The method that should return those 3 values is Calculate_every_1_min and is also declared below:

Inside my MainWindow.h , I declare the struct and the method

private:
    Ui::MainWindow *ui;

    struct final_average_s{
        float minute_30;
        float minute_60;
        float hour_24;
    };

    final_average_s Calculate_every_1_min(uint32_t sample_counter_1_sec,float avg_1_min);

Inside MainWindow.cpp the method Calculate_every_1_min is defined:

final_average_s MainWindow::Calculate_every_1_min(uint32_t sample_counter_1_sec,float avg_1_min){
    final_average_s final_average; // create local struct variable to return it
    index_30_min = ((sample_counter_1_sec/60)%30); // index 30 min will consists of 30 1 minute samples
    qDebug("index 30 min = %u \n",index_30_min);


    index_60_min = ((sample_counter_1_sec/60)%60); // index 60 min will consists of 60 1 minute samples
    qDebug("index 60 min = %u \n",index_60_min);

    index_24_hr = ((sample_counter_1_sec/60)%1440); // index 60 min will consists of 60 1 minute samples
    qDebug("index 24 hr = %u \n",index_24_hr);


    current_30_min_avg[index_30_min-1] = avg_1_min;
    current_60_min_avg[index_60_min-1] = avg_1_min;
    current_24_hr_avg[index_24_hr-1] = avg_1_min;

    final_average.minute_30 = calculate_30_min_average(sample_counter,index_30_min,current_30_min_avg);
    ui->minute_30_edit->setText(QString::number(final_average.minute_30));

    final_average.minute_60 = calculate_60_min_average(sample_counter,index_60_min,current_60_min_avg);
    ui->minute_30_edit->setText(QString::number(final_average.minute_60));

    final_average.hour_24 = calculate_24_hr_average(sample_counter,index_24_hr,current_24_hr_avg);
    ui->minute_30_edit->setText(QString::number(final_average.hour_24));

    return final_average;

And then this function is being called:

final_average_s final_average = Calculate_every_1_min(sample_counter_1_sec,avg_1_min);

Everything seems okay to me but I am getting the following issues:



../uCurrent/mainwindow.cpp: At global scope:
../uCurrent/mainwindow.cpp:836:1: error: 'final_average_s' does not name a type
  836 | final_average_s MainWindow::Calculate_every_1_min(uint32_t sample_counter_1_sec,float avg_1_min){
      | ^~~~~~~~~~~~~~~
mingw32-make[1]: *** [Makefile.Debug:2827: debug/mainwindow.o] Error 1
mingw32-make[1]: *** Waiting for unfinished jobs....
mingw32-make[1]: Leaving directory 'C:/Users/petrikas.lu/Desktop/WORK/QT/uCurrent/build-uCurrent-Desktop_Qt_6_4_0_MinGW_64_bit-Debug'
mingw32-make: *** [Makefile:45: debug] Error 2
08:28:56: The process "C:\Qt\Tools\mingw1120_64\bin\mingw32-make.exe" exited with code 2.
Error while building/deploying project uCurrent (kit: Desktop Qt 6.4.0 MinGW 64-bit)
When executing step "Make"

I do not quite understand what the compiler means by saying final_average_s does not name a type. Any help is appreciated!

jsulm

@lukutis222 said in Returning struct from class method:

final_average_s MainWindow::Calculate_every_1_min(uint32_t sample_counter_1_sec,float avg_1_min){

Change to:

MainWindow::final_average_s MainWindow::Calculate_every_1_min(uint32_t sample_counter_1_sec,float avg_1_min){

else compiler does not know what final_average_s is because it is defined inside MainWindow.

lukutis222

@jsulm said in Returning struct from class method:

MainWindow::final_average_s

Issue fixed. Thank you very much