f2 is taking it’s arguments by reference, which is essentially an alias for the arguments you pass. The difference between pointer and reference is that a reference cannot be NULL. With the f you need to pass the address (using & operator) of the parameters you’re passing to the pointer, where when you pass by reference you just pass the parameters and … Read more
The problem is circular dependency. set.h includes set.cpp and set.cpp includes set.h.Remember that including a file simply pastes its code. There is no need for set.cpp to know about set.h as they will be one file when compiling.Also, you shouldn’t call set.cpp a cpp file. cpp files are ones that are meant to generate object … Read more
It’s short for “warn all” — it turns on (almost) all the warnings that g++ can tell you about. Typically a good idea, especially if you’re a beginner, because understanding and fixing those warnings can help you fix lots of different kinds of problems in your code.
The ‘friend’ concept is useful in Java, for example, to separate an API from its implementation. It is common for implementation classes to need access to API class internals but these should not be exposed to API clients. This can be achieved using the ‘Friend Accessor’ pattern as detailed below: The class exposed through the … Read more
The symlink to the 4.8.2 directory is nothing to worry about, it’s normal for the libstdc++ headers on Red Hat Enterprise Linux (and therefore CentOS) to be arranged like that. gcc –version will tell you the version of the gcc executable in your path. rpm -q libstdc++-devel will tell you the version of the package … Read more
When I do this: Everything works great. However, when I make it a vector of references instead: I get horrible errors like error C2528: ‘pointer’ : pointer to reference is illegal I want to put a bunch of references to structs into a vector, so that I don’t have to meddle with pointers. Why is … Read more
else doesn’ take any condition, but you’ve written this: which doesn’t do what you intend it to do. You want to do thos: Notice the difference. Also, there can be at most one else block, associated with an if block Or a chain of if, else-if, else-if blocks. That is, you can write this: Or, … Read more
new type requires deletenew type[size] requires delete []Using one instead of the other is wrong. Btw you should not use such raw pointers like this unless you have a very good reason. Use std::vector or std::array instead. And 2D MxN arrays should generally be linearised into 1D M*N arrays, also using these containers.
Could you provide a whole makefile? But right now I can tell – you should check that “install” target already exists. So, check Makefile whether it contains a line. If not, there is no such target and so make has right. Probably you should use just “make” command to compile and then use it as … Read more
The short answer for this is, “because that’s what the C++ standard specifies”. Note that you can always specify a constructor that’s different from the default, like so: The default constructor of the base class is called only if you don’t specify which one to call.