C++ Optional
C++17 optional SAMPLE for clangd fixtures.
#include <iostream>
#include <optional>
std::optional<int> parse(int n) {
if (n < 0) return std::nullopt;
return n * 2;
}
int main() {
std::cout << parse(21).value_or(-1) << "\n";
}
Specifications
- Language
- cpp
- Role
- idiomatic sample
- Line Endings
- LF
- Wave
- G
What is a .cpp file?
C++ (.cpp) is a plain-text source file for the C++ programming language — a statically typed, compiled language that extends C with classes, templates, operator overloading, the Standard Template Library, and RAII. It is used for high-performance applications, game engines, and systems software.
How to use this file
Use an example .cpp file to test syntax highlighters, C++ compilers (g++, clang++), static analysers and formatters, and parser or language-detection tooling against real language constructs.
How to use this file for testing
“C++ Optional” is a deterministic Novus Examples fixture for Syntax highlighting, Code parsing, Editor testing. Idiomatic hello-world programs and realistic snippets across sixteen languages, exercising comments, string escapes, interpolation, numeric literals, and language keywords — for testing syntax highlighters, editor themes, and tree-sitter grammars.
Documented properties for this file: idiomatic sample · cpp · LF. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
This is a short, known-correct source file. Run it through your syntax highlighter, linter, formatter, tree-sitter grammar, or parser, and open it in the in-browser editor to tweak and re-download. Each snippet exercises comments, string escapes, literals, and language keywords.
Code examples
c++ -std=c++20 optional_sample.cpp -o prog && ./progRelated files
- cppC++ — Hello WorldThe classic hello-world in C++ — iostream and std::cout — for testing highlighters, C++ compilers, and parsers.

- cppC++ — Series (class template, STL)A realistic C++ snippet with a class template, STL algorithms (max_element, accumulate), std::move, and range handling — for testing highlighters, g++/clang++, and parsers against real templates.

- cC — Hello WorldThe classic hello-world in C — an include, main, and printf — for testing highlighters, C compilers, and parsers against the canonical first program.

- cC — Linked list (structs, malloc, pointers)A realistic C program: a singly linked list with a typedef struct, malloc/free memory management, pointer walking, and error handling — for testing highlighters, compilers, and static analysers.

- cC StructC struct SAMPLE for clangd / highlighter fixtures.

- csC# FibonacciA small C# iterator Fibonacci utility — realistic snippet for language tooling.

Generated by generation/code_wave_g.py. Free for any use, no attribution required — license.