## Back to Basics: Templates – Part 2 Bob Steagall CppCon 2021 KEWB COMPUTING ## Recap: Templates ## • C++ supports generic programming with templates • A template is a parametrized description of ## • C++ provides six kinds of templates • Function templates • Class templates • Member function templates • Alias template • Variable templates • Lambda templates ## Recap: Translation Units • program must contain exactly one definition of every non-inline variable or function that is used in the program - For an inline variable or an inline function, a definition is required in every translation

## Back to Basics: Templates – Part 1 Bob Steagall CppCon 2021 KEWB COMPUTING ## Overview ## • Rationale • Template fundamentals • Template categories in detail ## Goals and References ## • Goals some important terminology and concepts • Point to next steps ## • Recommended references • C++ Templates The Complete Guide, Second Edition David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor – Addison-Wesley to be known as generic programming C++ supports generic programming with templates ## Template Categories ## Function Templates (C++98/03) ## • Recipes for making functions template T const&

## B2B: C++ Templates Part 2  Andreas Fertig @Andreas_Fertig https://AndreasFertig.Info post@AndreasFertig.Info ## ## V ariadic templates: Parameter pack ## ■ Syntax: A typename|class... Ts generates a type template parameter pack with optional name. B Args... ts a function argument parameter pack with optional name static_assert(min(3, 2) == 2); ## V ariadic templates ## ■ With C++11, there are variadic templates: Variadic templates are templates that take any number of parameters. - Already known by

## B2B: C++ Templates Part 1  Andreas Fertig https://AndreasFertig.Info post@AndreasFertig.Info @Andreas_Fertig 9/d/b/69db0b3fef72f7b5c9930083cfbd2a95/p2_1.jpg) ## Templates Templates are a kind of pattern for the compiler. ■ We can instantiate templates with different types or values. Each instantiation for argument. Templates reduce a lot of writers' work. We do not have to implement functions multiple times just because it's a slightly different type. There are different types of templates: Function-templates

138 3 Triggers 392 4 Events 408 5 Event correlation 412 6 Visualization 421 7 Templates 458 8 Templates out of the box 459 9 Notifications upon events 478 10 Macros 533 11 Users and user 13. Problem acknowledgment 592 14. Configuration export/import 594 1 Host groups 596 2 Templates 596 3 Hosts 620 4 Network maps 645 5 Screens 654 15. Discovery 661 1 Network discovery monitoring, once in the database • apply templates to monitored devices ## Use of templates • grouping checks in templates • templates can inherit other templates ## Network discovery • automatic discovery

partition: @startuml start partition Initialization { :read config file; :init internal variable; } partition Running { :wait for user interaction; :print information; } stop @enduml jpg) ### 17.4 Multilines You can use : and ; to have multilines box. @startmindmap * Class Templates **:Example 1 template class cname{ void f1() ... } variable definition instead. – !define should be replaced by return !function – !definelong should be replaced