C++ template constructor

There is no way to explicitly specify the template arguments when calling a constructor template, so they have to be deduced through argument deduction. This is because if you say: The <int> is the template argument list for the type Foo, not for its constructor. There’s nowhere for the constructor template’s argument list to go. … Read more

“used without template parameters”

VisitedSet is a template, not a class, so you can’t use VisitedSet in a nested name specifier such as VisitedSet::getSize(). Just as you specified the declaration of class VisitedSet<T> for all class T, you must specify the definition of VisitedSet<T>::getSize() for all class T: The name of a template can, however, be used as though it were a class within a template definition: In this case, Example is short … Read more

Flask raises TemplateNotFound error even though template file exists

You must create your template files in the correct location; in the templates subdirectory next to the python module (== the module where you create your Flask app). The error indicates that there is no home.html file in the templates/ directory. Make sure you created that directory in the same directory as your python module, and that you did in fact … Read more

Difference of keywords ‘typename’ and ‘class’ in templates?

typename and class are interchangeable in the basic case of specifying a template: and are equivalent. Having said that, there are specific cases where there is a difference between typename and class. The first one is in the case of dependent types. typename is used to declare when you are referencing a nested type that depends on another template parameter, such as the typedef in … Read more