An introduction to C++ template programming

About this course

This concise, example-led overview introduces the essential ideas and practical techniques of C++ template programming. It focuses on writing reusable, type-safe code through generic programming, explaining how templates implement parametric polymorphism and enable powerful compile-time computations. The guide balances clear explanations with annotated code examples and hands-on exercises so you can move from fundamentals to more advanced template patterns with confidence.

Educational context

Designed for programmers who want to adopt modern C++ generic techniques, the material suits learners at the beginner-to-intermediate level and supports progression into template metaprogramming. It emphasizes idiomatic usage, readable template design, and techniques that align with contemporary C++ (including C++20 concepts). The presentation is practical: theory is motivated by real coding problems and resolved with tested examples.

What you'll learn

• How to author and instantiate function and class templates to reduce duplication and improve flexibility.
• When to use parametric (compile-time) polymorphism versus runtime polymorphism and how each affects design and performance.
• How to apply template specialization and partial specialization to tailor behavior for particular types.
• Introductory template metaprogramming techniques for compile-time calculation and type manipulation using type traits and constexpr logic.
• How to use modern features—variadic templates, SFINAE idioms, and C++20 concepts—to constrain templates and produce clearer diagnostics.
• Practical debugging strategies, common pitfalls, and best practices for maintainable, efficient template code.

Key topics covered

The guide intertwines conceptual explanations with practical examples: defining templates, type deduction rules, crafting class templates and template-based inheritance, and using specialization to optimize or correct behavior. It introduces type traits and SFINAE to conditionally enable functionality, explains variadic templates for flexible interfaces, and highlights how C++20 concepts can simplify constraints and improve compiler messages.

Who this guide is for

Students and developers new to templates will gain a solid foundation in mechanics and motivations. Intermediate C++ engineers will find concrete patterns and exercises that deepen their approach to generic libraries and API design. Developers familiar with C++ can use the metaprogramming and concepts material as a springboard for writing performant, type-safe utilities and libraries.

Practical applications

• Implement generic data structures and algorithms that are reusable across types without duplicating code.
• Build type-safe utilities—such as serializers, comparators, or logging helpers—that adapt via traits or specialization.
• Design high-performance abstractions that move work to compile time and provide clearer static guarantees.

Common mistakes to avoid

• Overcomplicating designs with unnecessary templates—prefer simplicity unless genericity is needed.
• Ignoring compiler diagnostics; learn to read template instantiation traces and use static_assert for clearer errors.
• Failing to constrain templates, which can lead to ambiguous overloads or surprising instantiations; use concepts or SFINAE where appropriate.

Practice exercises and next steps

Exercises include implementing generic containers and algorithms, creating specializations for edge cases, and experimenting with compile-time utilities. Suggested next steps: practice with C++20 concepts, study standard type traits, and examine established template libraries to learn idiomatic patterns and performance techniques.

Based on the work of Hayo Thielecke, this resource pairs theory with hands-on practice to help you apply templates confidently in real-world C++ development. Download the PDF to try the examples and continue building your template programming skills.