options.h

#ifndef SOURCEMETA_CORE_OPTIONS_H_
#define SOURCEMETA_CORE_OPTIONS_H_
 
#ifndef SOURCEMETA_CORE_OPTIONS_EXPORT
#include <sourcemeta/core/options_export.h>
#endif
 
// NOLINTBEGIN(misc-include-cleaner)
#include <sourcemeta/core/options_error.h>
// NOLINTEND(misc-include-cleaner)
 
#include <cstddef>          // std::size_t
#include <initializer_list> // std::initializer_list
#include <memory>           // std::unique_ptr
#include <string>           // std::string
#include <string_view>      // std::string_view
#include <unordered_map>    // std::unordered_map
#include <unordered_set>    // std::unordered_set
#include <vector>           // std::vector

 
namespace sourcemeta::core {

struct OptionsModifiers {
  std::size_t skip{0};
};

class SOURCEMETA_CORE_OPTIONS_EXPORT Options {
public:
  Options() = default;
  // Disallow copies given the unique pointers
  Options(const Options &) = delete;
  auto operator=(const Options &) -> Options & = delete;
  Options(Options &&) noexcept = default;
  auto operator=(Options &&) noexcept -> Options & = default;

  auto option(std::string &&name, std::initializer_list<std::string> aliases)
      -> void;

  auto flag(std::string &&name, std::initializer_list<std::string> aliases)
      -> void;

  [[nodiscard]] auto at(const std::string_view name) const
      -> const std::vector<std::string_view> &;

  [[nodiscard]] auto contains(const std::string_view name) const -> bool;

  [[nodiscard]] auto positional() const
      -> const std::vector<std::string_view> &;

  auto parse(const int argc,
             // We want to be compatible with `main`s `argv`
             // NOLINTNEXTLINE(modernize-avoid-c-arrays)
             const char *const argv[], const OptionsModifiers options = {})
      -> void;
 
private:
// Exporting symbols that depends on the standard C++ library is considered
// safe.
// https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-2-c4275?view=msvc-170&redirectedfrom=MSDN
#if defined(_MSC_VER)
#pragma warning(disable : 4251 4275)
#endif
  static constexpr std::string_view POSITIONAL_ARGUMENT_NAME{""};
  static const std::vector<std::string_view> EMPTY;
 
  std::vector<std::unique_ptr<std::string>> storage;
  std::unordered_map<std::string_view, std::string_view> aliases_;
  std::unordered_map<std::string_view, std::vector<std::string_view>> options_;
  std::unordered_set<std::string_view> flags;
#if defined(_MSC_VER)
#pragma warning(default : 4251 4275)
#endif
};
 
} // namespace sourcemeta::core
 
#endif // SOURCEMETA_CORE_OPTIONS_H_