Embedded Programming with Modern C++ Cookbook

How to do it...

We are going to create an application that uses the power of the C++ standard library algorithms to generate and process fixed data frames without using dynamic memory allocation: 

1. In your working directory, ~/test, create a subdirectory called expected.
2. Use your favorite text editor to create an expected.cpp file in the expected subdirectory.
3. Add includes and a new type definition to the expected.cpp file:

#include <iostream>#include <system_error>#include <variant>#include <unistd.h>#include <sys/fcntl.h>template <typename T>class Expected {  std::variant<T, std::error_code> v;public:  Expected(T val) : v(val) {}  Expected(std::error_code e) : v(e) {}  bool valid() const {    return std::holds_alternative<T>(v);  }  const T& value() ...