/* * @topic T00252 <span style="background-color: yellow;">New: </span> header files, header guards, and multiple source files * @brief Function declarations */ // Pre-processor macro TO_UPPERCASE_H_INCLUDED becomes the "header guard" // that prevents the content of the header file to be included more than once // Things that begin with # are pre-processor directives: #ifndef TO_UPPERCASE_H_INCLUDED #define TO_UPPERCASE_H_INCLUDED // More examples of pre-processor directives: #define GREETING "hello" #ifdef GREETING #define SALUTATION "Ms." #endif // The #include is a directive, too: #include <iostream> #include <string> // using declarations: using std::string; using std::cout; // Function declarations: void pause(); string to_uppercase( string str ); #endif// TO_UPPERCASE_H_INCLUDED