Run two instances of a SFML C++ app in Xcode

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  Our C++ application, that runs on Linux, links to dynamic libraries built by us. When everything is built using gcc 7.3.0 with switch -std=c++98, the libraries load ok. However, when I build without that switch (i.e. with C++11) I get an undefined symbol:

  undefined symbol: _ZTIN8StarLibs7LinkSim2NR13StarOfdmGenNRE ( typeinfo for StarLibs::LinkSim::NR::StarOfdmGenNR )
  

  The demangled symbol name is in brackets.

  What could cause missing typeinfo, which is apparently for the class?

  The class has methods that return const. Also the class's header file #includes another class's header file and that included class contains some static const members. I tried declaring those members in a separate .cpp file to allocate them storage (that recipe fixed a similar error in another part of the code) but it did not fix this problem.
• How does this variadic template with using work?

  I have this code snippet and am trying to understand how it works:

  #include <iostream>
  
  class GenBase
  {
  public:
      void BaseClass()
      {
          std::cout << " BaseClass " << std::endl;
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  template <class Base>
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  template <typename Type>
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  1. using BaseType = General<typename BaseHelper<Types... >::BaseType>

     Why do we need ::BaseType at the end?

  2. What type would BaseType contain in OurClass if we instantiate it with OurClass<int,float,Test>?
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  class NonCopyable {
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          NonCopyable() = default;
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          NonCopyable(NonCopyable const&)                 = delete;
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  Platform :

  Debian 9

  GCC 6.3.0

  Compilation flags :

  -fpermissive -ggdb -std=c++11
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          if (player.playerSprite.getPosition().x <= 0) //Left
                  player.playerSprite.setPosition(0.f, player.playerSprite.getPosition().y);
  
          if (player.playerSprite.getPosition().x >= window.getSize().x - player.playerSprite.getGlobalBounds().width) //Right
              player.playerSprite.setPosition(window.getSize().x - player.playerSprite.getGlobalBounds().width, player.playerSprite.getPosition().y);
  
          if (player.playerSprite.getPosition().y <= 0) //Top
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      player.playerSprite.setPosition(player.playerSprite.getPosition().x, window.getSize().y - player.playerSprite.getGlobalBounds().height);
  

  The left and top are working fine (the sprite collides into them but not pass through) but the sprite won't even come near the right and the bottom sides. Any idea how to fix this?
• String input in SFML errors

  So I want to create a loop in which I input a string (so that later on I can draw text from that string on the screen) the command is not "q" then we keep inputting string. Each time a string is input, there will be a new SFML window open.

  However, it seems to be an infinite loop with an "underflow" error. I wonder if you can help me with the logic of my code. Thanks a lot!

  int main(){ 
      char command;
      cout << "Enter command: [S]tart     [Q]uit" << endl;
      cin >> command;
  
      // Get the string input
      while (command != 'q'){
          cout << "Enter string: ";
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          cin.ignore(numeric_limits<streamsize>::max(), '\n');
          getline (cin, s);
          cout << "The string is: " << s << endl;
  
  
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          window.create(sf::VideoMode(1500, 1500), "SFML works");
          while (window.isOpen()){
              sf::Event event;
  
              while (window.pollEvent(event)){
                  switch (event.type){
                      case sf::Event::Closed:
                          window.close();
  
                          break;
                  }
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              window.clear();
              window.display();
  
          }
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• Write text input on the screen in SFML (C++)

  So I'm creating a graphing calculator. I have an input string s. From the string, I can graph it using SFML. I start from the a MIN x-coordinate to a MAX x-coordinate, get the corresponding y from a EvaluateString() method, and all the coordinates to a VertexArray v. I wrote my method and the graphing method already and it all worked well.

  However, I have a small issue. I want to input my string on the screen, such as "sin(cos(tan(x)))" like this. I'm struggling to find a way to do it. I kinda figured out it has to do with the event TextEntered, but still I can't find anything completely.

  Please suggest me a way. Thanks a lot!

  

  class Calculator{
  public:
      void main();
  private:
      WindowSize DefaultWindow;
      sf::RenderWindow window;
      Cartesian vertexX[2],vertexY[2];
      sf::Vertex axis[4];
      const double MAX = 10;
      const double MIN = -10;
      const double INCREMENT = 0.001;
  
  };
  
  int main(){ 
      DefaultWindow.Max = Cartesian(10,10);
      DefaultWindow.Min = Cartesian(-10,-10);
      DefaultWindow.plane.width=1500;
      DefaultWindow.plane.height=1500;
  
      // Set up x and y-axis
      vertexX[0] = Cartesian(-100,0);
      vertexX[1] = Cartesian(100, 0);
      vertexY[0] = Cartesian(0,-100);
      vertexY[1] = Cartesian(0,100);
  
      axis[0] = sf::Vertex(convertCartesiantoWindow(vertexX[0],DefaultWindow));
      axis[1] = sf::Vertex(convertCartesiantoWindow(vertexX[1],DefaultWindow));
      axis[2] = sf::Vertex(convertCartesiantoWindow(vertexY[0],DefaultWindow));
      axis[3] = sf::Vertex(convertCartesiantoWindow(vertexY[1],DefaultWindow));
  
      // Set up the window
      window.create(sf::VideoMode(1500, 1500), "Graphing calculator");
  
      // Input string
      string s = "sin(cos(tan(x)))";
  
      // Stack c contains all the Cartesian coordinate vertices
      // Cartesian is a struct which contains x and y coordinates
      Stack<Cartesian> c;
  
      sf::VertexArray v;
  
      // For a certain function in string s, I evaluate it 
      // and return the y_coordinate from the function EvaluateString (s, i)
      // Push each (x,y) evaluated in the Stack c
      for (double i = MIN; i <= MAX; i+= INCREMENT)
          c.Push(Cartesian(i,EvaluateString(s,i)));
  
      // v is VertexArray which contains all the vertices (x,y)
      v = plot(DefaultWindow, c);
  
  
      while (window.isOpen()) {
          sf::Event event;
          while (window.pollEvent(event)) {
  
              switch (event.type) {
                  case sf::Event::Closed:
                      window.close();
                      break;
              }
          }
      }
  
      // Draw the graph
      window.clear(sf::Color::Black);
      window.draw(axis,4,sf::Lines);
      window.draw(v);
      window.display();
  }