Summary
This episode explores the 'extern template' feature added in C++11 and how it can significantly reduce compilation times. Jason demonstrates how template functions are normally instantiated in every translation unit that uses them, leading to redundant compilation work. By using 'extern template', developers can declare that a template instantiation will be provided elsewhere, preventing duplicate instantiations across files. The episode also discusses the trade-offs between compile-time performance and runtime optimization when combining 'extern template' with Link Time Optimization (LTO).