Template Metaprogramming: Type Traits Part 1 CppCon 2020 1 Jody Hagins
 jhagins@maystreet.com 
 coachhagins@gmail.comTemplate Metaprogramming: Type Traits CppCon 2020 2 IntroductionIntended Audience oriented: shallow depth, slow current • Not necessarily beginner to C++, but beginner to traditional template metaprogramming techniques 3Intended Audience • Beginner/Intermediate • Gentle entry: swimming oriented: shallow depth, slow current • Not necessarily beginner to C++, but beginner to traditional template metaprogramming techniques • Type traits part of standard library for ~10 years 3Intended Audience

1 / 58Template Metaprogramming (TMP) Template Metaprogramming (TMP) template using meta_fun = this_talk; 2 / 58❓static_assert(Template::Metaprogramming::is_hard); // ✔ 3 / 58❓s 58❓static_assert(Template::Metaprogramming::is_hard); // ✔ ❓static_assert(Template::Metaprogramming::is_powerful); // ✔ 3 / 58❓static_assert(Template::Metaprogramming::is_hard); // ✔ ❓static_assert( ❓static_assert(Template::Metaprogramming::is_powerful); // ✔ ❓static_assert(( Template::Metaprogramming::is_easy and Template::Metaprogramming::is_powerful and Template::Metaprogramming::has_nice_error_messages

abstract… • « Our game programmers and game engines involve fights between heroes and their foes […] » 3From the abstract… • « Our game programmers and game engines involve fights between heroes and their and monsters to hit at each other […] » 4From the abstract… • « Our game programmers and game engines involve fights between heroes and their foes. There are «classical», traditional ways to express other. This is what this talk will explore » 5From the abstract… • « Our game programmers and game engines involve fights between heroes and their foes. There are «classical», traditional ways to express

with different layouts or built-in components, and choose them for each page as required. A page’s template can be switched for another at any time. You’ll find the site’s templates in tutorial-project/m tutorial-project/mysite/mysite/templates. By default, pages in your site will use the fullwidth.html template, the first one listed in the project’s settings.py CMS_TEMPLATES tuple: CMS_TEMPLATES = ( ## Customize this in an HTML template that will be filled with content from the database when the page is rendered. This content is edited using django CMS’s frontend editing mechanism, using Django template tags. fullwidth

required. A page’s template can be switched for another at any time. You’ll find the site’s templates in mysite/templates. By default, pages in your site will use the fullwidth.html template, the first one in an HTML template that will be filled with content from the database when the page is rendered. This content is edited using django CMS’s frontend editing mechanism, using Django template tags. fullwidth see {% load cms_tags %} in that file - cms_tags is the required template tag library. If you’re not already familiar with Django template tags, you can find out more in the Django documentation [https://docs

needed to meet different disaster tolerance levels. • Real-time HTAP TiDB provides two storage engines: TiKV, a row-based storage engine, and TiFlash, a columnar storage engine. TiFlash uses the Multi-Raft in the table as the national character set. 2.4.2.12 Storage engines TiDB allows for tables to be created with alternative storage engines. Despite this, the metadata as described by TiDB is for the InnoDB restart 6. Create and start the cluster: Edit the configuration file according to the following template, and name it as topo. �→ yaml: 97 # # Global variables are applied to all deployments and used

needed to meet different disaster tolerance levels. • Real-time HTAP TiDB provides two storage engines: TiKV, a row-based storage engine, and TiFlash, a columnar storage engine. TiFlash uses the Multi-Raft in the table as the national character set. 2.4.2.12 Storage engines TiDB allows for tables to be created with alternative storage engines. Despite this, the metadata as described by TiDB is for the InnoDB restart 6. Create and start the cluster: Edit the configuration file according to the following template, and name it as topo. �→ yaml: 97 # # Global variables are applied to all deployments and used

needed to meet different disaster tolerance levels. • Real-time HTAP TiDB provides two storage engines: TiKV, a row-based storage engine, and TiFlash, a columnar storage engine. TiFlash uses the Multi-Raft in the table as the national character set. 2.4.2.12 Storage engines TiDB allows for tables to be created with alternative storage engines. Despite this, the metadata as described by TiDB is for the InnoDB restart 6. Create and start the cluster: Edit the configuration file according to the following template, and name it as topo. �→ yaml: 100 # # Global variables are applied to all deployments and used

needed to meet different disaster tolerance levels. • Real-time HTAP TiDB provides two storage engines: TiKV, a row-based storage engine, and TiFlash, a columnar storage engine. TiFlash uses the Multi-Raft in the table as the national character set. 2.4.2.12 Storage engines TiDB allows for tables to be created with alternative storage engines. Despite this, the metadata as described by TiDB is for the InnoDB restart 6. Create and start the cluster: Edit the configuration file according to the following template, and name it as topo. �→ yaml: 127 # # Global variables are applied to all deployments and used

needed to meet different disaster tolerance levels. • Real-time HTAP TiDB provides two storage engines: TiKV, a row-based storage engine, and TiFlash, a columnar storage engine. TiFlash uses the Multi-Raft in the table as the national character set. 2.4.2.12 Storage engines TiDB allows for tables to be created with alternative storage engines. Despite this, the metadata as described by TiDB is for the InnoDB restart 6. Create and start the cluster: Edit the configuration file according to the following template, and name it as topo. �→ yaml: # # Global variables are applied to all deployments and used as