cpp / expert
Snippet
Recursive Template Loop Unrolling
A sophisticated control flow pattern that forces the compiler to unroll loops at compile time using template recursion. This eliminates runtime branch overhead for fixed-size operations.
snippet.cpp
cpp
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template <size_t N>struct LoopUnroller {template <typename Func>static constexpr void apply(Func&& f) {LoopUnroller<N - 1>::apply(f);f(std::integral_constant<size_t, N - 1>{});}};template <>struct LoopUnroller<0> {template <typename Func>static constexpr void apply(Func&&) {}};// Usagevoid optimize() {LoopUnroller<4>::apply([](auto i) {// Code here is unrolled at compile timeprocess_element(i.value);});}
Breakdown
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f(std::integral_constant<size_t, N - 1>{});
Passes the loop index as a compile-time constant, allowing the lambda to use it in static contexts.
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template <> struct LoopUnroller<0>
The base case for recursion that terminates the unrolling process.