std::enable_if (C++)
First saw this at Tesla.
How this is implemented under the hood?
template<bool Condition, typename T = void>
struct enable_if {
// "type" is not defined if "Condition == false"
};
template<typename T>
struct enable_if<true, T> {
using type = T;
};
template <typename T>
using std::enable_if_t = typename std::enable_if<T>::type;