You got very close. I added a few bits because they’re handy class ParameterBase { public: virtual ~ParameterBase() {} template<class T> const T& get() const; //to be implimented after Parameter template<class T, class U> void setValue(const U& rhs); //to be implimented after Parameter }; template <typename T> class Parameter : public ParameterBase { public: Parameter(const … Read more
In addition to non-C++20 answer, if you are, by any chance, able to use C++20 and its concepts feature, I would suggest you the following implementation: #include <iostream> #include <concepts> enum class MyEnum { A, B, C }; template <typename T> concept IntegralOrEnum = std::same_as<MyEnum, T> || std::integral<T>; template <IntegralOrEnum T> bool isFunction(T const& aVariable) … Read more
Why GCC and Clang think they are right K, which is the injected class name, has a dual nature in the scope of K<int>. You can use it without template arguments. Then it refers to K<int> (to its own type). It can be followed by a template argument list too. IMO it’s reasonable to say … Read more
It’s what it says. Your template parameter list says that M is a class, not a template. If you say that it’s a class template, then everything’s fine: template <class C, template <class C> class M> class BlockCipherGenerator : public KeyGenerator { M<C> m_cipher; }; Remember, something like std::vector is not a class, but a … Read more
enable_if works because the substitution of a template argument resulted in an error, and so that substitution is dropped from the overload resolution set and only other viable overloads are considered by the compiler. In your example, there is no substitution occurring when instantiating the member functions because the template argument T is already known … Read more
You can do similar things using JSP tag files. Create your own page.tag that contains the page structure. Then use a <jsp:body/> tag to insert the contents.
I had the same problem too. It’s a simple answer. This retrieves the last five items in site.posts: {% for recent in site.posts[-5:] %} {% for post in recent %} <li> <a href=”https://stackoverflow.com/{{ post.url }}”>{{ post.title }}</a></li> {% endfor %} {% endfor %}
The reason for this is that the app_directories loader is essentially the same as adding each app’s template folder to the TEMPLATE_DIRS setting, e.g. like TEMPLATE_DIRS = ( os.path.join(PROJECT_PATH, ‘app1’, ‘templates’), os.path.join(PROJECT_PATH, ‘app2’, ‘template’), … os.path.join(PROJECT_PATH, ‘templates’), ) The problem with this is that as you mentioned, the index.html will always be found in app1/templates/index.html … Read more
There are different levels of template specialization: 1) Template declaration (no specialization) template <class Key, class Value> struct Foo {}; 2) Partial specialization template <class Key> struct Foo<Key, int> {}; 3) Full/explicit specialization template <> struct Foo<std::string, int> {}; Then, when instantiating the templates, the compiler will choose the most specialized definition available: Foo<std::string, std::string> … Read more
You can use && and ||, which will end up working just like the ternary operators. {{item.isValid && ‘Valid’ || ‘Invalid’ }} EDIT: Angular introduced ternary operators in 1.1.5: {{item.isValid ? ‘Valid’ : ‘Invalid’ }}