cpp / expert
Snippet
SFINAE with std::enable_if
Substitution Failure Is Not An Error (SFINAE) allows the compiler to discard template overloads that would result in invalid code. std::enable_if_t leverages this to enable a function only when a specific compile-time condition (like being an integer) is met.
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template <typename T>std::enable_if_t<std::is_integral_v<T>, T>increment(T value) {return value + 1;}// Usage:// auto a = increment(5); // Compiles// auto b = increment(3.14); // Compiler Error
Breakdown
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std::enable_if_t<std::is_integral_v<T>, T>
Evaluates the condition; if true, the type is T; if false, this overload is discarded.
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std::is_integral_v<T>
A type trait that checks if T is a built-in integral type.