C++ Comments and Documentation Standards: From Single-Line to Doxygen

Comments are human-readable annotations embedded within source code. They are completely ignored by the compiler and are vital for explaining the intent, algorithms, and assumptions behind complex C++ implementations.

The Two Built-in C++ Comment Syntaxes

// 1. Single-Line Comment: Extends from // to the end of the current line

/* 2. Multi-Line Comment:
      Spans across multiple lines
      Ideal for longer algorithmic explanations */

Professional Standard: Doxygen API Documentation

Enterprise C++ codebases require structured documentation comments formatted using Doxygen tags:

/**
 * @file math_utils.h
 * @brief High-performance mathematical utility functions.
 * @author Veewom Engineering Team
 */

/**
 * @brief Computes the factorial of a positive integer recursively.
 * @param n A non-negative integer.
 * @return The calculated factorial as an unsigned 64-bit integer.
 * @throws std::invalid_argument If n exceeds 20 (causing 64-bit overflow).
 */
unsigned long long calculateFactorial(int n) {
    if (n <= 1) return 1;
    return n * calculateFactorial(n - 1);
}