Does the ‘mutable’ keyword have any purpose other than allowing a data member to be modified by a const member function?

It allows the differentiation of bitwise const and logical const. Logical const is when an object doesn’t change in a way that is visible through the public interface, like your locking example. Another example would be a class that computes a value the first time it is requested, and caches the result. Since c++11 mutable … Read more

C++ Member Initializer List

Just to clarify something that came up in some of the other answers… There is no requirement that the initializer list be in either the source (.cpp) or header (.h) file. In fact, the compiler does not distinguish between the two types of files. The important distinction is between the contructor’s declaration and it’s definition. … Read more

How to bind an unbound method without calling it?

All functions are also descriptors, so you can bind them by calling their __get__ method: bound_handler = handler.__get__(self, MyWidget) Here’s R. Hettinger’s excellent guide to descriptors. As a self-contained example pulled from Keith’s comment: def bind(instance, func, as_name=None): “”” Bind the function *func* to *instance*, with either provided name *as_name* or the existing name of … Read more

jQuery match part of class with hasClass

You can use the startswith CSS3 selector to get those divs: $(‘div[class^=”project”]’) To check one particular element, you’d use .is(), not hasClass: $‘[class^=”project”]’) For using the exact /project\d/ regex, you can check out jQuery selector regular expressions or use /(^|\s)project\d(\s|$)/.test($el.attr(“class”))

Wrapping C++ class API for C consumption

Foreach public method you need a C function. You also need an opaque pointer to represent your class in the C code. It is simpler to just use a void* though you could build a struct that contains a void* and other information (For example if you wanted to support arrays?). Fred.h ——————————– #ifdef __cplusplus … Read more

What are the advantages that prototype based OO has over class based OO?

The advantage of prototypal inheritance is that it potentially allows fancy metaprogramming in a straightforward way because the prototype chain is easily manipulated. This is a rather academic advantage because metaprogramming is the wrong answer 99% of the time. As an example, you could have a Javascript Key-Value Observer style data manipulation layer with a … Read more

.class vs .java

A .class file is a compiled .java file. .java is all text and is human readable. .class is binary (usually). You compile a java file into a class file by going to the command line, navigating to the .java file, and running javac “c:\the\path\to\your\file\” You must have a java SDK installed on your computer (get … Read more

Dynamic class in Angular.js

You can simply assign a function as an expression and return proper class from there. Edit: there is also better solution for dynamic classes. Please see note below. Snippet from view: <div ng-class=”appliedClass(myObj)”>…</div> and in the controller: $scope.appliedClass = function(myObj) { if (myObj.someValue === “highPriority”) { return “special-css-class”; } else { return “default-class”; // Or … Read more