const is pointless when the argument is passed by value since you will not be modifying the caller’s object. Wrong. It’s about self-documenting your code and your assumptions. If your code has many people working on it and your functions are non-trivial then you should mark const any and everything that you can. When writing … Read more
The function name g_atomic_int_compare_and_exchange_full is in parentheses. What’s the significance of this? Putting a function name in brackets avoids any macro expansion in case there is a function like macro with the same name. That means, g_atomic_int_compare_and_exchange_full(…) will use the macro while (g_atomic_int_compare_and_exchange_full)(…) will use the function. Why is this used? You cannot assign a … Read more
You cannot define a function using a typedef for a function type. It’s explicitly forbidden – refer to 6.9.1/2 and the associated footnote: The identifier declared in a function definition (which is the name of the function) shall have a function type, as specified by the declarator portion of the function definition. The intent is … Read more
Yes, there are limits imposed by the implementation. Your answer is given in the bold text in the following excerpt from the C++ Standard. 1. C++ Language Annex B – Implementation quantities Because computers are finite, C + + implementations are inevitably limited in the size of the programs they can successfully process. Every implementation … Read more
According to the C++17 standard (11.3.6 Default arguments) 9 A default argument is evaluated each time the function is called with no argument for the corresponding parameter. A parameter shall not appear as a potentially-evaluated expression in a default argument. Parameters of a function declared before a default argument are in scope and can hide … Read more
Functions can only be declared constexpr if they obey the rules for constexpr — no dynamic casts, no memory allocation, no calls to non-constexpr functions, etc. Declaring a function in the standard library as constexpr requires that ALL implementations obey those rules. Firstly, this requires checking for each function that it can be implemented as … Read more
A definition of a function is also a declaration of a function. The purpose of a declaring a function is to make it known to the compiler. Declaring a function without defining it allows a function to be used in places where it is inconvenient to define it. For example: If a function is used … Read more
CoffeeScript uses function declarations (aka “named functions”) in just one place: class definitions. For instance, class Foo compiles to var Foo; Foo = (function() { function Foo() {} return Foo; })(); The reason CoffeeScript doesn’t use function declarations elsewhere, according to the FAQ: Blame Microsoft for this one. Originally every function that could have a … Read more
It is not obvious why one is not allowed; nested functions were proposed a long time ago in N0295 which says: We discuss the introduction of nested functions into C++. Nested functions are well understood and their introduction requires little effort from either compiler vendors, programmers, or the committee. Nested functions offer significant advantages, […] … Read more
The question you are asking is really two questions, not one. Most replies so far tried to cover the entire thing with a generic blanket “this is K&R style” answer, while in fact only a small part of it has anything to do with what is known as K&R style (unless you see the entire … Read more