The varying line-ending characters don’t matter, assuming the file is open in text mode, which is what you get unless you ask for binary. The compiled program will write out the correct thing for the system compiled for. The only difference is that std::endl flushes the output buffer, and ‘\n’ doesn’t. If you don’t want … Read more
The compilation of a C++ program involves three steps: Preprocessing: the preprocessor takes a C++ source code file and deals with the #includes, #defines and other preprocessor directives. The output of this step is a “pure” C++ file without pre-processor directives. Compilation: the compiler takes the pre-processor’s output and produces an object file from it. … Read more
The do … while and if … else are there to make it so that a semicolon after your macro always means the same thing. Let’s say you had something like your second macro. #define BAR(X) f(x); g(x) Now if you were to use BAR(X); in an if … else statement, where the bodies of … Read more
Short answer: in order to make x a dependent name, so that lookup is deferred until the template parameter is known. Long answer: when a compiler sees a template, it is supposed to perform certain checks immediately, without seeing the template parameter. Others are deferred until the parameter is known. It’s called two-phase compilation, and … Read more
The C++ standard does not specify the size of integral types in bytes, but it specifies minimum ranges they must be able to hold. You can infer minimum size in bits from the required range. You can infer minimum size in bytes from that and the value of the CHAR_BIT macro that defines the number … Read more
I guess this document might serve as a not so short introduction : n3055 The whole massacre began with the move semantics. Once we have expressions that can be moved and not copied, suddenly easy to grasp rules demanded distinction between expressions that can be moved, and in which direction. From what I guess based … Read more
POD stands for Plain Old Data – that is, a class (whether defined with the keyword struct or the keyword class) without constructors, destructors and virtual members functions. Wikipedia’s article on POD goes into a bit more detail and defines it as: A Plain Old Data Structure in C++ is an aggregate class that contains … Read more
There are two widely-used memory allocation techniques: automatic allocation and dynamic allocation. Commonly, there is a corresponding region of memory for each: the stack and the heap. Stack The stack always allocates memory in a sequential fashion. It can do so because it requires you to release the memory in the reverse order (First-In, Last-Out: … Read more
Put yourself in the compiler’s position: when you forward declare a type, all the compiler knows is that this type exists; it knows nothing about its size, members, or methods. This is why it’s called an incomplete type. Therefore, you cannot use the type to declare a member, or a base class, since the compiler … Read more
Most vexing parse This is related to what is known as “C++’s most vexing parse”. Basically, anything that can be interpreted by the compiler as a function declaration will be interpreted as a function declaration. Another instance of the same problem: std::ifstream ifs(“file.txt”); std::vector<T> v(std::istream_iterator<T>(ifs), std::istream_iterator<T>()); v is interpreted as a declaration of function with … Read more