Learn D - 10 Code Examples & CST Typing Practice Test
D is a high-level, statically typed, compiled systems programming language combining C-like performance with modern features like garbage collection, functional programming, and meta-programming.
Learn D with Real Code Examples
Updated Nov 20, 2025
Architecture
Compiled to native code
Supports both garbage-collected and manual memory management
Modules and packages organize code
Templates and mixins allow code reuse and metaprogramming
Contracts and unit tests improve reliability
Rendering Model
Source code compiled to native binaries
Modules organize code into packages
Templates and mixins generate code at compile-time
Contracts and unittest blocks enforce correctness
Binaries executed across platforms natively
Architectural Patterns
Procedural and functional pipelines
OOP for encapsulation
Compile-time code generation using templates/mixins
Range-based iteration
Module/package-based project organization
Real World Architectures
Game engines and physics simulations
High-performance computing
Web backends with Vibe.d
Financial and trading applications
System utilities and CLI tools
Design Principles
C-like syntax with modern safety features
Multi-paradigm: imperative, OOP, functional
Compile-time metaprogramming with templates and mixins
Garbage collection for managed memory
Focus on performance and expressiveness
Scalability Guide
Use modules/packages for large projects
Leverage templates and mixins for reusable code
Profile performance-critical sections
Optimize memory usage
Parallelize tasks where possible
Migration Guide
Port older D1 code to D2
Refactor templates for modern syntax
Update deprecated standard library usage
Test performance after migration
Ensure cross-platform compatibility
Frequently Asked Questions about D
What is D?
D is a high-level, statically typed, compiled systems programming language combining C-like performance with modern features like garbage collection, functional programming, and meta-programming.
What are the primary use cases for D?
Systems programming and OS-level development. High-performance computing. Game engines and graphics programming. Financial and trading applications. Compile-time code generation and metaprogramming
What are the strengths of D?
High-performance native code. Clean modern syntax with C-style familiarity. Powerful compile-time metaprogramming. Versatile multi-paradigm language. Rich standard library with ranges and algorithms
What are the limitations of D?
Smaller community and ecosystem than C++ or Rust. Less industrial adoption for large-scale projects. Limited GUI library support. Garbage collector can be unpredictable in real-time systems. Interfacing with C++ can be complex
How can I practice D typing speed?
CodeSpeedTest offers 10+ real D code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.