Understanding template specialization

A template specialization is the definition created from a template instantiation. The template that is being specialized is called the primary template. You can provide an explicit specialized definition for a given set of template arguments, therefore overwriting the implicit code the compiler would generate instead. This is the technique that powers features such as type traits and conditional compilation, which are metaprogramming concepts we will explore in Chapter 5, Type Traits and Conditional Compilation.

There are two forms of template specialization: explicit (full) specialization and partial specialization. We will look in detail at these two in the following sections.

Explicit specialization

Explicit specialization (also called full specialization) occurs when you provide a definition for a template instantiation with the full set of template arguments. The following can be fully specialized:

• Function templates
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