Header File lex/spelling.hpp

The file spelling.hpp contains the class lex::token_spelling, which is the (string) spelling of a token.

class token_spelling
{
public:
    explicit token_spelling(const char* ptr, std::size_t size);
    
    // access
    char operator[](std::size_t i) const noexcept;
    
    const char* begin() const noexcept;
    const char* end() const noexcept;
    
    const char* data() const noexcept;
    std::size_t size() const noexcept;
};

// comparison
bool operator==(token_spelling lhs, token_spelling rhs);
bool operator!=(token_spelling lhs, token_spelling rhs);

bool operator==(token_spelling lhs, const char* rhs);
bool operator==(const char* lhs, token_spelling rhs);
bool operator!=(token_spelling lhs, const char* rhs);
bool operator!=(const char* lhs, token_spelling rhs);

It is a simple, fully constexpr and noexcept replacement of std::string_view.