Maximum number of parameters in function declaration

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

What is the purpose of the “volatile” keyword appearing inside an array subscript?

The volatile keyword is used to declare an array type of a function parameter. Here, double x[volatile] is equivalent to double * volatile x. The cppreference says : In a function declaration, the keyword volatile may appear inside the square brackets that are used to declare an array type of a function parameter. It qualifies … Read more

What do * (single star) and / (slash) do as independent parameters? [duplicate]

There is a new function parameter syntax / to indicate that some function parameters must be specified positionally and cannot be used as keyword arguments.[This is new in Python 3.8] Documentation specifies some of the use cases/benefits of positional-only parameters. It allows pure Python functions to fully emulate behaviors of existing C coded functions. For … Read more

How to deal with name/value pairs of function arguments in MATLAB

I prefer using structures for my options. This gives you an easy way to store the options and an easy way to define them. Also, the whole thing becomes rather compact. function example(varargin) %# define defaults at the beginning of the code so that you do not need to %# scroll way down in case … Read more

How to create a polyvariadic haskell function?

The key points of printf is the ability to either return a String or a function. Copied from http://www.haskell.org/ghc/docs/6.12.2/html/libraries/base-4.2.0.1/src/Text-Printf.html, printf :: (PrintfType r) => String -> r printf fmts = spr fmts [] class PrintfType t where spr :: String -> [UPrintf] -> t instance (IsChar c) => PrintfType [c] where spr fmts args = … Read more

Skipping optional function parameters in JavaScript

Solution: goog.net.XhrIo.send(url, undefined, undefined, undefined, {‘Cache-Control’: ‘no-cache’}) You should use undefined instead of optional parameter you want to skip, because this 100% simulates the default value for optional parameters in JavaScript. Small example: myfunc(param); //is equivalent to myfunc(param, undefined, undefined, undefined); Strong recommendation: use JSON if you have a lot of parameters, and you can … Read more

Proper way to receive a lambda as parameter by reference

You cannot have an auto parameter. You basically have two options: Option #1: Use std::function as you have shown. Option #2: Use a template parameter: template<typename F> void f(F && lambda) { /* … */} Option #2 may, in some cases, be more efficient, as it can avoid a potential heap allocation for the embedded … Read more

How to get function parameter names/values dynamically?

The following function will return an array of the parameter names of any function passed in. var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg; var ARGUMENT_NAMES = /([^\s,]+)/g; function getParamNames(func) { var fnStr = func.toString().replace(STRIP_COMMENTS, ”); var result = fnStr.slice(fnStr.indexOf(‘(‘)+1, fnStr.indexOf(‘)’)).match(ARGUMENT_NAMES); if(result === null) result = []; return result; } Example usage: getParamNames(getParamNames) // returns [‘func’] getParamNames(function (a,b,c,d){}) // … Read more