src/gromacs/utility/flags.h

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  35 /*! \file
  36  * \brief
  37  * Declares gmx::FlagsTemplate.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_FLAGS_H
  44 #define GMX_UTILITY_FLAGS_H
  45
  46 namespace gmx
  47 {
  48
  49 /*! \brief
  50  * Template class for typesafe handling of combination of flags.
  51  *
  52  * \tparam FlagType An enumerated type that holds the possible single flags.
  53  *
  54  * This class is not used publicly, but is present in an installed header
  55  * because it is used internally in public template classes.
  56  *
  57  * Currently, it is not completely transparent, since or'ing together two
  58  * \p FlagType flags does not automatically create a FlagsTemplate object.
  59  * Also, some operators and more complex operations (like testing for multiple
  60  * flags at the same time) are missing, but can be added if the need arises.
  61  *
  62  * \inlibraryapi
  63  * \ingroup module_utility
  64  */
  65 template <typename FlagType>
  66 class FlagsTemplate
  67 {
  68     public:
  69         //! Creates a flags object with no flags set.
  70         FlagsTemplate() : flags_(0) {}
  71         //! Creates a flags object from a single flag.
  72         FlagsTemplate(FlagType flag) : flags_(flag) {}
  73
  74         /*! \brief
  75          * Tests if the given flag is set.
  76          *
  77          * Note that if \p flag has more than a single bit set, then returns
  78          * true if any of them is set.
  79          */
  80         bool test(FlagType flag) const { return (flags_ & flag) != 0; }
  81         //! Clears all flags.
  82         void clearAll() { flags_ = 0; }
  83         //! Sets the given flag.
  84         void set(FlagType flag) { flags_ |= flag; }
  85         //! Clears the given flag.
  86         void clear(FlagType flag) { flags_ &= ~flag; }
  87         //! Sets or clears the given flag.
  88         void set(FlagType flag, bool bSet)
  89         {
  90             if (bSet)
  91             {
  92                 set(flag);
  93             }
  94             else
  95             {
  96                 clear(flag);
  97             }
  98         }
  99
 100         //! Combines flags from two flags objects.
 101         FlagsTemplate<FlagType>
 102         operator|(const FlagsTemplate<FlagType> &other) const
 103         {
 104             return FlagsTemplate<FlagType>(flags_ | other.flags_);
 105         }
 106         //! Combines flags from another flag object.
 107         FlagsTemplate<FlagType> &
 108         operator|=(const FlagsTemplate<FlagType> &other)
 109         {
 110             flags_ |= other.flags_;
 111             return *this;
 112         }
 113         //! Combined flags from two flags objects.
 114         FlagsTemplate<FlagType>
 115         operator&(const FlagsTemplate<FlagType> &other) const
 116         {
 117             return FlagsTemplate<FlagType>(flags_ & other.flags_);
 118         }
 119         //! Returns an object with all flags flipped.
 120         FlagsTemplate<FlagType> operator~() const
 121         {
 122             return FlagsTemplate<FlagType>(~flags_);
 123         }
 124
 125     private:
 126         //! Creates a flags object with the given flags.
 127         explicit FlagsTemplate(unsigned long flags) : flags_(flags) {}
 128
 129         unsigned long           flags_;
 130 };
 131
 132 } // namespace gmx
 133
 134 #endif