Placeholder Image

字幕表 動画を再生する

  • Class templates allow class members to use template parameters as types. They are created

  • in the same way as function templates, but unlike functions templates a class template

  • must always be instantiated with the template parameter explicitly specified. Another thing

  • to remember when using class templates is that if we define a method outside of the

  • class template we must then also precede that definition with the template declaration.

  • Note that the template parameter between the angle brackets after the class name specifies

  • that the function's template parameter is the same as the class’s template parameter.

  • In addition to type parameters, templates can also have regular function-like parameters.

  • As an example, we can add an integer parameter that is used to decide the size of an array.

  • When we now instantiate this class template we have to include both a type and an integer.

  • Similar to function arguments template parameters can also be given default values and types.

  • To use these defaults we just need to leave the angle brackets empty when instantiating

  • the class template.

  • If we want to define a different implementation for a template, when a specific type is passed

  • as the template parameter, we can declare a template specialization. For example, in

  • this class template there is a print method that outputs the variable A. Say that when

  • the template parameter is a bool we would like it to print outtrueorfalse

  • instead of 1 or 0. One way to do this would be to create a class template specialization.

  • We then create a reimplementation of the class template where the template parameter list

  • empty. Instead we place a <bool> specialization parameter after the class template’s name

  • and we use this data type instead of the template parameter throughout the implementation. When

  • we now instantiate this class template with a boolean template type this template specialization

  • will be used instead of the standard one.

  • Note that there is no inheritance of members from the generic template to the specialized

  • template. We have to redefine the whole class. In this case, since there is only one function

  • that is different between the templates, a better alternative would instead be to create

  • a function template specialization. This way we only need to redefine the print method

  • and not the whole class.

Class templates allow class members to use template parameters as types. They are created

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B2 中上級

C++チュートリアル - 34 - テンプレートII (C++ Tutorial - 34 - Templates II)

  • 71 8
    Jie Rong Lin に公開 2021 年 01 月 14 日
動画の中の単語