SimplifyC++

Article by Ayman Alheraki on January 11 2026 10:37 AM

#9 Modern C++ and Rust Programming – A Comparative Educational Guide from Concepts to Applications

Your First Program

Hello World in both C++ and Rust

Introduction: The Traditional “Hello World”

The “Hello World” program is the canonical starting point for learning any programming language. It serves as a simple example to illustrate the basic syntax for outputting text to the console, and it often reveals fundamental language concepts like compilation, program structure, and standard library usage.

This section compares the “Hello World” program in both Modern C++ (using C++17/20 conventions) and Rust (edition 2021), providing insight into language syntax, compilation, and execution.

Hello World in Modern C++


#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

Explanation:

#include : This directive includes the standard input/output stream library, which contains std::cout for console output (cppreference.com).
int main(): The entry point of the C++ program, returning an integer status code to the operating system. return 0; conventionally means successful execution (ISO C++ Standard).
std::cout << "Hello, World!" << std::endl;: Streams the string literal "Hello, World!" to the standard output, followed by a newline (std::endl). The std:: prefix specifies the use of the standard namespace (cplusplus.com).

Compilation and Execution:

Compiled with a C++ compiler such as GCC, Clang, or MSVC using a command like:


fn main() {
    println!("Hello, World!");
}

Modern C++ compilers fully support the standard library and optimizations, ensuring the program is eﬀicient with minimal startup overhead (GCC 12 release notes).

Hello World in Rust

Explanation:

fn main(): The entry point of the Rust program, which returns the unit type () implicitly. Rust functions are declared with fn (Rust Reference).
println!("Hello, World!");: Macro that prints text to the console, automatically appending a newline. Macros in Rust use an exclamation mark !. The macro provides formatting support similar to printf but with compile-time checks (Rust Standard Library).

Compilation and Execution:

Compiled with the Rust compiler rustc:


xxxxxxxxxx
rustc hello.rs
./hello

The Rust compiler performs aggressive optimizations and ensures memory safety at compile time. The latest Rust 1.70 release (2023) continues to improve compile times and executable performance (Rust Blog).

Key Comparative Points

Aspect	C++ “Hello World”	Rust “Hello World”
Program entry point	int main() with explicit return	fn main() returns unit type implicitly
Output syntax	Stream-based std::cout and<< operator	Macro-based println! with formatting
Header inclusion	Requires explicit #include	No header inclusion, core macros are built-in
Memory safety	Manual memory safety, not an issue for simple output	Guaranteed memory safety, even in complex programs
Compilation command	g++ -std=c++17 or equivalent	rustc
Language paradigm	Multi-paradigm: procedural, object-oriented, generic	Multi-paradigm: procedural, functional, ownership-based
Error handling	Return codes from main and exceptions	Implicit unit return; error handling via Result and macros