string_view.hpp

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#ifndef TABLEAU_HYPER_STRING_VIEW_HPP
#define TABLEAU_HYPER_STRING_VIEW_HPP
 
#if !defined(__cplusplus) || (__cplusplus < 201703L) /* Use own string view if C++ is older than C++17 */
#define hyper_use_own_string_view
#endif
 
#ifdef hyper_use_own_string_view
#include <cstring>
#include <ostream>
#include <string>
#else
#include <string_view>
#endif
 
namespace hyperapi {
#ifdef hyper_use_own_string_view
class string_view final {
   public:
   string_view(const char* data, size_t length) noexcept
      : data_(data), length_(length) {
   }
 
   string_view(const char* c)
      : data_(c), length_(std::strlen(c)) {
   }
 
   string_view(const std::string& s)
      : data_(s.data()), length_(s.size()) {
   }
 
   size_t size() const noexcept { return length_; }
   const char* data() const noexcept { return data_; }
 
   int compare(const string_view& other) const noexcept;
 
   operator std::string() const { return std::string(data(), size()); }
 
   friend bool operator==(const string_view& a, const string_view& b) noexcept { return a.compare(b) == 0; }
   friend bool operator>(const string_view& a, const string_view& b) noexcept { return a.compare(b) > 0; }
   friend bool operator!=(const string_view& a, const string_view& b) noexcept { return !(a == b); }
   friend bool operator<(const string_view& a, const string_view& b) noexcept { return (b > a); }
   friend bool operator<=(const string_view& a, const string_view& b) noexcept { return (a == b) || (a < b); }
   friend bool operator>=(const string_view& a, const string_view& b) noexcept { return (a == b) || (a > b); }
 
   friend std::ostream& operator<<(std::ostream& os, const string_view& v) { return os.write(v.data(), static_cast<long>(v.size())); }
 
   bool empty() { return length_ == 0; }
 
   private:
   const char* data_ = nullptr;
 
   size_t length_ = 0;
};
}
 
namespace std {
 
template <>
struct hash<hyperapi::string_view> {
   size_t operator()(const hyperapi::string_view& sv) const noexcept;
};
}
#else /* C++17 or greater */
using string_view = std::string_view;
}
#endif
 
#ifdef hyper_use_own_string_view
#include <hyperapi/impl/string_view.impl.hpp>
#endif
 
#endif