How do I reduce compile times for heavy templates in C++?

Reducing compile times for heavy templates in C++ can be crucial for improving the development experience. Here are several strategies to optimize template-heavy code and minimize the compile time:

• Use Forward Declarations: Instead of including headers, forward declare classes when possible. This reduces the dependencies and speeds up compilation.
• Template Specialization: Specialize templates for common types to avoid heavy template instantiation costs.
• Reduce Template Depth: Try to minimize the complexity of template parameters. Deep template hierarchies can lead to longer compile times.
• Precompiled Headers: Use precompiled headers for frequently used templates to speed up compilation.
• Use `constexpr`: Utilize `constexpr` as it can allow certain computations to occur at compile time, reducing runtime dependencies.
• Template Instantiation Control: Control template instantiations explicitly to avoid unnecessary generations.