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> operator|(const FlagsTemplate<FlagType>& other) const
 102     {
 103         return FlagsTemplate<FlagType>(flags_ | other.flags_);
 104     }
 105     //! Combines flags from another flag object.
 106     FlagsTemplate<FlagType>& operator|=(const FlagsTemplate<FlagType>& other)
 107     {
 108         flags_ |= other.flags_;
 109         return *this;
 110     }
 111     //! Combined flags from two flags objects.
 112     FlagsTemplate<FlagType> operator&(const FlagsTemplate<FlagType>& other) const
 113     {
 114         return FlagsTemplate<FlagType>(flags_ & other.flags_);
 115     }
 116     //! Returns an object with all flags flipped.
 117     FlagsTemplate<FlagType> operator~() const { return FlagsTemplate<FlagType>(~flags_); }
 118
 119 private:
 120     //! Creates a flags object with the given flags.
 121     explicit FlagsTemplate(unsigned long flags) : flags_(flags) {}
 122
 123     unsigned long flags_;
 124 };
 125
 126 } // namespace gmx
 127
 128 #endif