Modern C++ Programming Cookbook

How to do it...

Use constexpr if statements to do the following:

• To avoid using  std::enable_if and relying on SFINAE to impose restrictions on function template types and conditionally compile code:

        template <typename T>         auto compute(T const a, T const b)         {           if constexpr (std::is_integral<T>::value)             return a * b;           else              return a + b;         }

• To simplify writing variadic templates and implement metaprogramming compile-time recursion:

        namespace binary         {           using byte8 = unsigned char;           namespace binary_literals           {             namespace binary_literals_internals             {                         template <typename CharT, char d, char... bits>               constexpr CharT binary_eval()               {                 if constexpr(sizeof...(bits) == 0)                    return static_cast<CharT>(d-'0');                 else if constexpr(d == '0')