I don’t think it will make a significant difference in compile time but #pragma once is very well supported across compilers but not actually part of the standard. The preprocessor may be a little faster with it as it is more simple to understand your exact intent. #pragma once is less prone to making mistakes and it is … Read more
The first constructor in the header should not end with a semicolon. #include <string> is missing in the header. string is not qualified with std:: in the .cpp file. Those are all simple syntax errors. More importantly: you are not using references, when you should. Also the way you use the ifstream is broken. I suggest learning C++ before trying to use it. … Read more
I am running Eclipse Helios and I have g++-4.6 installed. Hope I am not wrong that g++4.6 implements C++ 11 features. I have created a C++ project which uses the nullptr and auto keywords. The build gives the following errors:- Actually it was building fine until yesterday. I am getting these from nowhere today. Please … Read more
I believe that should do what you need.
Your problem with the first version is that your compiler is trying to prevent a bug. Your problem with the second version is that you outsmarted your compiler and successfully managed to create a bug. Given your constructor, you want to store pointers to the float values that are passed by reference. Since your second … Read more
You may want to start with just the first part, create the class with two constructors, one if they give the two numbers, and one that defaults to 1. Then, write the four functions, the assignment is nice enough to give you the equations. If a denominator is ever equal to zero then I would … Read more
I am not able to understand the differences between std::string and std::wstring. I know wstring supports wide characters such as Unicode characters. I have got the following questions: When should I use std::wstring over std::string? Can std::string hold the entire ASCII character set, including the special characters? Is std::wstring supported by all popular C++ compilers? … Read more
You need to #include <cstdlib> Source: http://en.cppreference.com/w/cpp/utility/program/system Also, try to avoid system, it’s dangerous. To pause the program when it’s finished, put a breakpoint on the } at the end of main. There isn’t a standard way to clear the screen unfortunately. For future reference, the red squiggles are intellisense errors, which are shown by a different front-end than the one that … Read more
Base class constructors are automatically called for you if they have no argument. If you want to call a superclass constructor with an argument, you must use the subclass’s constructor initialization list. Unlike Java, C++ supports multiple inheritance (for better or worse), so the base class must be referred to by name, rather than “super()”. … Read more
Move the to a cpp file. If you have it in a header, then every .cpp that includes it will have a copy and you will get the duplicate symbol error during the link.