C++C++17Code SnippetLanguage FeatureLearn C++

Tutorial: Easily Learn To Use optional In Modern C++ On Windows

young lady typing on keyboard of laptop in living room

Optional definition (std::optional) manages an optional contained value, i.e. a value that may or may not be present. This class template comes with C++17 standard, it is used with CLANG and other C++ compilers which has this standard. A common use case for optional is the return value of a function that may fail. Any instance of optional<T> at any given point in time either contains a value or does not contain a value. If an optional<T> contains a value, the value is guaranteed to be allocated as part of the optional object footprint, i.e. no dynamic memory allocation ever takes place. Thus, an optional object models an object, not a pointer, even though operator*() and operator->() are defined.

C++ Builder supports C++17 standards with its CLANG compiler and Bcc Compiler. Optional can be used to define any type of variables as below;

An optional variable can be checked by has_value() method if it has a value or not.

Value optional variable can be obtained by value() property and or value_or(0) method that returns 0 if no value. This C++ Builder VCL Windows application example below explains all;

close

Oh hi there 👋
It’s nice to meet you.

Sign up to receive awesome C++ content in your inbox, every day.

We don’t spam! Read our privacy policy for more info.

About author

Dr. Yilmaz Yoru has 33+ years of coding with more than 30+ programming languages, mostly C++ on Windows, Android, Mac-OS, iOS, Linux, and some other operating systems. He was born in 1974, Eskisehir-Turkey, started coding in college and graduated from the department of Mechanical Engineering of Eskisehir Osmangazi University in 1997. He worked as a research assistant at the same university for more than 10 years. He received his MSc and PhD degrees from the same department at the same university. Since 2012, he is the founder and CEO of Esenja LLC Company. He has married and he is a father of a son. Some of his interests are Programming, Thermodynamics, Fluid Mechanics, Artificial Intelligence, 2D & 3D Designs, and high-end innovations.
Related posts
C++C++11C++14C++17Learn C++Templates

Learn How To Eliminate Pointers In Templates in C++

C++C++11C++14C++17Learn C++Templates

Learn To Export And Import Template Members From A DLL Or A Package In C++

C++C++11C++14C++17Learn C++Templates

What Is A Function Template In C++?

C++C++11C++14C++17Learn C++Templates

What Is A Class Template In C++?

Worth reading...
Introduction To C++ Windows Development With C++Builder