C++ бағдарламалау тіліндегі үлгілер

Feature in the C++ programming language

Templates are a feature of the C++ programming language that allows functions and classes to operate with generic types. This allows a function or class declaration to reference via a generic variable another different class (built in or newly declared data type) without creating full declaration for each of these different classes. In plain terms, a templated class or function would be the equivalent of (before "compiling") copying and pasting the templated block of code where it is used, and then replacing the template parameter with the actual one. For this reason, classes employing templated methods place the implementation in the headers (*. h files) as no symbol could be compiled without knowing the type beforehand. The C++ Standard Library provides many useful functions within a framework of connected templates. Major inspirations for C++ templates were the parameterized modules provided by the language CLU and the generics provided by Ada.

There are three kinds of templates: function templates, class templates and, since C++14, variable templates. Since C++11, templates may be either variadic or non variadic; in earlier versions of C++ they are always non variadic.

A class template provides a specification for generating classes based on parameters. Class templates are generally used to implement containers. A class template is instantiated by passing a given set of types to it as template arguments. The C++ Standard Library contains many class templates, in particular the containers adapted from the Standard Template Library, such as vector.

When a function or class is instantiated from a template, a specialization of that template is created by the compiler for the set of arguments used, and the specialization is referred to as being a generated specialization.

C++11 introduced variadic templates, which can take a variable number of arguments in a manner somewhat similar to variadic functions such as std::printf.