Article by Ayman Alheraki in January 24 2025 01:40 PM
The Modules feature in C++20 is one of the most significant modern additions to the language, aimed at improving how code is organized and managed in large projects. However, C++ still lacks an effective package management system, unlike other programming languages such as Rust (with Cargo) or Go (with Go Modules). In this article, we will discuss the importance of the Modules feature, how it could impact the development of an effective package manager in C++, and whether it will solve the package management problem in the future.
Modules are a new way to organize code in C++ that aim to replace the old header file system (e.g., #include
). They offer the following benefits:
Better Isolation: Each Module is an independent unit, reducing unnecessary dependencies between files.
Improved Compilation Time: Modules are compiled only once, reducing compilation time compared to header files, which are included multiple times.
Enhanced Performance: Reduced redundancy and better memory management during compilation.
// math.cppm
export module math;
export int add(int a, int b) {
return a + b;
}
// main.cpp
import math;
int main() {
int result = add(3, 4);
return 0;
}
Despite the power of C++, it lacks a standard and effective package management system. This leads to several issues:
Difficulty Managing Dependencies: Developers must manually download and manage libraries or use external tools like Conan or vcpkg.
Incompatibility Issues: Dependencies between different libraries may conflict, making large project management complex.
Lack of Integration: There is no unified system for package management, making working with external libraries less seamless compared to other languages.
Modules alone do not solve the package management problem, but they pave the way for significant improvements that could facilitate the development of an effective package management system in the future. Here’s how Modules can contribute:
Modules provide a more organized way to manage code, making it easier to define dependencies between different units. This could make package management more efficient.
With better isolation of units, conflicts between different libraries can be reduced, making dependency management easier.
Reduced compilation time and improved performance can make building large projects faster, which is essential for an effective package management system.
Although Modules are a step in the right direction, C++ needs additional components to create an effective package management system:
A Standard Dependency Management System: Like Cargo
in Rust or npm
in JavaScript.
A Centralized Library Repository: A unified place to host and access libraries.
Integrated Build Tools: Tools that support Modules and simplify project building and dependency management.
Let’s compare the current state of C++ with some other languages that have effective package management systems:
Cargo is Rust’s standard package manager. It supports downloading dependencies, building projects, and managing versions.
crates.io Repository: A centralized repository for libraries, making it easy to find and add libraries to projects.
Go Modules is Go’s dependency management system. It supports library versions and provides a unified way to manage dependencies.
pkg.go.dev Repository: A centralized repository for finding libraries.
npm is JavaScript’s standard package manager. It supports millions of libraries and provides powerful tools for managing dependencies.
To solve the package management problem in C++, the following steps could be taken:
Create a Standard Package Manager: Like Cargo
in Rust, supporting dependency downloading and version management.
Establish a Centralized Repository: A unified place to host and access libraries.
Improve Existing Tools: Such as Conan
and vcpkg
, to make them more integrated with Modules.
Community Support: This evolution requires strong support from the community and developers.
The Modules feature in C++20 is a significant step toward improving code organization and dependency management, but it does not solve the package management problem on its own. To create an effective package management system in C++, Modules must be part of a larger system that includes:
A standard dependency management system.
A centralized library repository.
Integrated build tools.
If these steps are achieved, C++ could become more competitive with modern languages like Rust and Go in the area of package management. However, this evolution requires significant effort from the community and developers to realize.