Overloader< Fs > Struct Template Reference

Used for overloading lambdas, useful for lambda-SFINAE. More...

#include <Overloader.hpp>

Detailed Description

template<class... Fs>
struct Overloader< Fs >

Used for overloading lambdas, useful for lambda-SFINAE.

struct my_type1 {
  int func(int a) { return 2 * a; }
};
 
struct my_type2 {};
 
template <class T, class = std::void_t<>>
struct has_func : std::false_type {};
 
template <class T>
struct has_func<
    T, std::void_t<decltype(std::declval<T>().func(std::declval<int>()))>>
    : std::true_type {};
 
template <class T>
void func(T t) {
  auto my_lambdas =
      Overloader{[](auto& /*f*/, std::integral_constant<bool, false>,
                    std::integral_constant<bool, false>) { return 0; },
                 [](auto& /*f*/, std::integral_constant<bool, true>,
                    std::integral_constant<bool, false>) { return 1; },
                 [](auto& /*f*/, std::integral_constant<bool, false>,
                    std::integral_constant<bool, true>) { return 2; },
                 [](auto& /*f*/, std::integral_constant<bool, true>,
                    std::integral_constant<bool, true>) { return 3; }};
  CHECK(static_cast<int>(has_func<T>::value) ==
        (my_lambdas(t, std::integral_constant<bool, has_func<T>::value>{},
                    std::integral_constant<bool, false>{})));
  CHECK(2 + static_cast<int>(has_func<T>::value) ==
        (my_lambdas(t, std::integral_constant<bool, has_func<T>::value>{},
                    std::integral_constant<bool, true>{})));
}
 
void caller() {
  func(my_type1{});
  func(my_type2{});
}

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The documentation for this struct was generated from the following file:

• src/Utilities/Overloader.hpp