instantiation

What exactly is “broken” with Microsoft Visual C++'s two-phase template instantiation?

由 五迷三道 提交于 2019-11-26 00:38:17
问题 Reading questions, comments and answers on SO, I hear all the time that MSVC doesn\'t implement two-phase template lookup / instantiation correctly. From what I understand so far, MSVC++ is only doing a basic syntax check on template classes and functions and doesn\'t check that names used in the template have atleast been declared or something along those lines. Is this correct? What am I missing? 回答1: I'll just copy an example from my "notebook" int foo(void*); template<typename T> struct S

`new function()` with lower case “f” in JavaScript

由 纵饮孤独 提交于 2019-11-26 00:11:12
My colleague has been using "new function()" with a lower case "f" to define new objects in JavaScript. It seems to work well in all major browsers and it also seems to be fairly effective at hiding private variables. Here's an example: var someObj = new function () { var inner = 'some value'; this.foo = 'blah'; this.get_inner = function () { return inner; }; this.set_inner = function (s) { inner = s; }; }; As soon as "this" is used, it becomes a public property of someObj. So someObj.foo, someObj.get_inner() and someObj.set_inner() are all available publicly. In addition, set_inner() and get

Does python have an equivalent to Java Class.forName()?

由 我怕爱的太早我们不能终老 提交于 2019-11-25 23:44:45
I have the need to take a string argument and create an object of the class named in that string in Python. In Java, I would use Class.forName().newInstance() . Is there an equivalent in Python? Thanks for the responses. To answer those who want to know what I'm doing: I want to use a command line argument as the class name, and instantiate it. I'm actually programming in Jython and instantiating Java classes, hence the Java-ness of the question. getattr() works great. Thanks much. Reflection in python is a lot easier and far more flexible than it is in Java. I recommend reading this tutorial

Creating an instance using the class name and calling constructor

由 那年仲夏 提交于 2019-11-25 22:47:01
问题 Is there a way to create an instance of a particular class given the class name (dynamic) and pass parameters to its constructor. Something like: Object object = createInstance(\"mypackage.MyClass\",\"MyAttributeValue\"); Where \"MyAttributeValue\" is an argument to the constructor of MyClass . 回答1: Yes, something like: Class<?> clazz = Class.forName(className); Constructor<?> ctor = clazz.getConstructor(String.class); Object object = ctor.newInstance(new Object[] { ctorArgument }); That will

Create an instance of a class from a string

由 时光毁灭记忆、已成空白 提交于 2019-11-25 22:41:47
问题 Is there a way to create an instance of a class based on the fact I know the name of the class at runtime. Basically I would have the name of the class in a string. 回答1: Take a look at the Activator.CreateInstance method. 回答2: Its pretty simple. Assume that your classname is Car and the namespace is Vehicles , then pass the parameter as Vehicles.Car which returns object of type Car . Like this you can create any instance of any class dynamically. public object GetInstance(string
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