The compiler can evaluate the function printcbase() as this: void printcbase(cbase* b ){ int a = b->FooA(); // line 1 int b = b->FooB(); // line 2 std::cout << a; // line 3 std::cout << b; // line 4 stc::cout << std::endl; } or some of many permutatins of lines marked as 1 – 4. … Read more
The standard defines the following operator<< overload in the basic_ostream class template: basic_ostream<charT,traits>& operator<<( basic_ostream<charT,traits>& (*pf) (basic_ostream<charT,traits>&) ); Effects: None. Does not behave as a formatted output function (as described in 27.6.2.5.1). Returns: pf(*this). The parameter is a pointer to a function taking and returning a reference to a std::ostream. This means that you can … Read more
The canonical approach consists in defining your own streambuf. You should have a look at: Angelika LAnger’s articles on IOStreams derivation James Kanze’s articles on filtering streambufs boost.iostream for examples of application
I was spinning my head around how to do the same thing and i found out it’s actually not that hard. Basically just subclass the ostream and the streambuf objects, and construct the ostream with itself as the buffer. the virtual overflow() from std::streambuf will be called for every character sent to the stream. To … Read more
Use std::fixed stream manipulator: cout<<fixed<<“Bas ana: “<<x<<“\tSon faiz: “<<t<<“\tSon ana: “<<x+t<<endl;
std::cout << std::fixed << std::setw(11) << std::setprecision(6) << my_double; You need to add #include <iomanip> You need stream manipulators You may “fill” the empty places with whatever char you want. Like this: std::cout << std::fixed << std::setw(11) << std::setprecision(6) << std::setfill(‘0’) << my_double;
Use: cout << “a is ” << hex << (int) a <<“; b is ” << hex << (int) b << endl; And if you want padding with leading zeros then: #include <iomanip> … cout << “a is ” << setw(2) << setfill(‘0’) << hex << (int) a ; As we are using C-style casts, … Read more
You have declared your function as friend. It’s not a member of the class. You should remove Matrix:: from the implementation. friend means that the specified function (which is not a member of the class) can access private member variables. The way you implemented the function is like an instance method for Matrix class which … Read more
This is one of those frequently asked questions that have different approaches that are similar but not really the same. The three approaches differ in who you are declaring to be a friend of your function –and then on how you implement it. The extrovert Declare all instantiations of the template as friends. This is … Read more