Where possible, avoid type-erasure

Reason

Type erasure incurs an extra level of indirection by hiding type information behind a separate compilation boundary.

Example

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Exceptions: Type erasure is sometimes appropriate, such as for std::function.

Enforcement

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Note

T.def: Template definitions

A template definition (class or function) can contain arbitrary code, so only a comprehensive review of C++ programming techniques would cover this topic. However, this section focuses on what is specific to template implementation. In particular, it focuses on a template definition's dependence on its context.