I’m getting the error Trying to compile a project on QtCreator. It happens when I try to create an instance of an user defined class, Layer. That class consists of a header, layer.h, and a implementation, layer.cpp. It was tested and works in another programs. On my project, it is included in qtwidget.h and the error happens when I try … Read more
You must make Foo::comparator static or wrap it in a std::mem_fun class object. This is because lower_bounds() expects the comparer to be a class of object that has a call operator, like a function pointer or a functor object. Also, if you are using C++11 or later, you can also do as dwcanillas suggests and use a lambda function. C++11 also has std::bind too. Examples:
Well I threw together a test program that ran each of these methods 100,000 times, half on files that existed and half on files that didn’t. Results for total time to run the 100,000 calls averaged over 5 runs, Method Time exists_test0 (ifstream) 0.485s exists_test1 (FILE fopen) 0.302s exists_test2 (posix access()) 0.202s exists_test3 (posix stat()) 0.134s The stat() function provided the … Read more
An “incomplete class” is one declared but not defined. E.g. as opposed to You need to #include “wielrenner.h” in dokter.ccp
I’m pretty new to C++ and this site so there are bound to be errors. When I try to compile my code I get errors like error: missing template argument before ‘b’. I’ve been searching the world for answers for hours and it has led me here. My assignment is to implement a templated class Collection … Read more
You need to include the string library, you also need to provide a return type for your main function and your implementation may require you to declare an explicit return statement for main (some implementations add an implicit one if you don’t explicitly provide one); like so:
It looks to me as if this is due to a typo, and you should use the variable ‘j’ in the second loop. After the first loop, the variable ‘i’ contains the value 52, so it sounds expected that calling nums.at(i) would throw a std::out_of_range, since nums only contains 52 values, starting at index 0. … Read more
On my computer I have Windows 7 x86. I installed MinGW, I wrote the path but when I go in cmd.exe and write g++ -v it says: But when I write the make -v command it recognizes it. I need this for school, I work in Eclipse, I even installed the latest java(I saw it … Read more
First of all, this is how you should provide a definition for member functions of a class template: Secondly, those definitions cannot be put in a .cpp file, because the compiler won’t be able to instantiated them implicitly from their point of invocation. See, for instance,
EncodeAndSend is not a static function, which means it can be called on an instance of the class CPMSifDlg. You cannot write this: It should rather be called as: