In short, CRTP is when a class A has a base class which is a template specialization for the class A itself. E.g. template <class T> class X{…}; class A : public X<A> {…}; It is curiously recurring, isn’t it? 🙂 Now, what does this give you? This actually gives the X template the ability … 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
2022 Visual Studio 2022 is now a 64bit process so its location has changed to using Program Files instead. %ProgramFiles%\Microsoft Visual Studio\<year>\<edition>\Common7\IDE\ItemTemplates\CSharp\Code\1033\Class.cs Year Edition Absolute path 2022 Community %ProgramFiles%\Microsoft Visual Studio\2022\Community\Common7\IDE\ItemTemplates\CSharp\Code\1033\Class\Class.cs Enterprise %ProgramFiles%\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\ItemTemplates\CSharp\Code\1033\Class\Class.cs Professional %ProgramFiles%\Microsoft Visual Studio\2022\Professional\Common7\IDE\ItemTemplates\CSharp\Code\1033\Class\Class.cs 2017 through 2019 Visual Studio 2017 changed the directory location to use release year instead of … Read more
This should do the trick: <% if (typeof(date) !== “undefined”) { %> <span class=”date”><%= date %></span> <% } %> Remember that in underscore.js templates if and for are just standard javascript syntax wrapped in <% %> tags.
Yes, it is valid. As for making it work with functors as well, the usual solution is something like this instead: template <typename F> void doOperation(F f) { int temp=0; f(temp); std::cout << “Result is ” << temp << std::endl; } which can now be called as either: doOperation(add2); doOperation(add3()); See it live The problem … Read more
UPDATE 2018: C++20 will come with templated and conceptualized lambdas. The feature has already been integrated into the standard draft. UPDATE 2014: C++14 has been released this year and now provides Polymorphic lambdas with the same syntax as in this example. Some major compilers already implement it. At it stands (in C++11), sadly no. Polymorphic … Read more
All we know is “All instances of a any class shares the same java.lang.Class object of that type of class” e.g) Student a = new Student(); Student b = new Student(); Then a.getClass() == b.getClass() is true. Now assume Teacher t = new Teacher(); without generics the below is possible. Class studentClassRef = t.getClass(); But … Read more
Write a custom template filter: from django.template.defaulttags import register … @register.filter def get_item(dictionary, key): return dictionary.get(key) (I use .get so that if the key is absent, it returns none. If you do dictionary[key] it will raise a KeyError then.) usage: {{ mydict|get_item:item.NAME }}
This is how you do if/else in Mustache (perfectly supported): {{#repo}} <b>{{name}}</b> {{/repo}} {{^repo}} No repos 🙁 {{/repo}} Or in your case: {{#author}} {{#avatar}} <img src=”{{avatar}}”/> {{/avatar}} {{^avatar}} <img src=”/images/default_avatar.png” height=”75″ width=”75″ /> {{/avatar}} {{/author}} Look for inverted sections in the docs: https://github.com/janl/mustache.js#inverted-sections
I think you need to use template template syntax to pass a parameter whose type is a template dependent on another template like this: template <template<class> class H, class S> void f(const H<S> &value) { } Here, H is a template, but I wanted this function to deal with all specializations of H. NOTE: I’ve … Read more