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Diffstat (limited to 'deps/v8/src/base/flags.h')
| -rw-r--r-- | deps/v8/src/base/flags.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/deps/v8/src/base/flags.h b/deps/v8/src/base/flags.h new file mode 100644 index 0000000000..f3420ee536 --- /dev/null +++ b/deps/v8/src/base/flags.h @@ -0,0 +1,108 @@ +// Copyright 2014 the V8 project authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef V8_BASE_FLAGS_H_ +#define V8_BASE_FLAGS_H_ + +#include "src/base/compiler-specific.h" + +namespace v8 { +namespace base { + +// The Flags class provides a type-safe way of storing OR-combinations of enum +// values. The Flags<T, S> class is a template class, where T is an enum type, +// and S is the underlying storage type (usually int). +// +// The traditional C++ approach for storing OR-combinations of enum values is to +// use an int or unsigned int variable. The inconvenience with this approach is +// that there's no type checking at all; any enum value can be OR'd with any +// other enum value and passed on to a function that takes an int or unsigned +// int. +template <typename T, typename S = int> +class Flags FINAL { + public: + typedef T flag_type; + typedef S mask_type; + + Flags() : mask_(0) {} + Flags(flag_type flag) : mask_(flag) {} // NOLINT(runtime/explicit) + explicit Flags(mask_type mask) : mask_(mask) {} + + Flags& operator&=(const Flags& flags) { + mask_ &= flags.mask_; + return *this; + } + Flags& operator|=(const Flags& flags) { + mask_ |= flags.mask_; + return *this; + } + Flags& operator^=(const Flags& flags) { + mask_ ^= flags.mask_; + return *this; + } + + Flags operator&(const Flags& flags) const { return Flags(*this) &= flags; } + Flags operator|(const Flags& flags) const { return Flags(*this) |= flags; } + Flags operator^(const Flags& flags) const { return Flags(*this) ^= flags; } + + Flags& operator&=(flag_type flag) { return operator&=(Flags(flag)); } + Flags& operator|=(flag_type flag) { return operator|=(Flags(flag)); } + Flags& operator^=(flag_type flag) { return operator^=(Flags(flag)); } + + Flags operator&(flag_type flag) const { return operator&(Flags(flag)); } + Flags operator|(flag_type flag) const { return operator|(Flags(flag)); } + Flags operator^(flag_type flag) const { return operator^(Flags(flag)); } + + Flags operator~() const { return Flags(~mask_); } + + operator mask_type() const { return mask_; } + bool operator!() const { return !mask_; } + + private: + mask_type mask_; +}; + + +#define DEFINE_OPERATORS_FOR_FLAGS(Type) \ + inline Type operator&(Type::flag_type lhs, \ + Type::flag_type rhs)ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator&(Type::flag_type lhs, Type::flag_type rhs) { \ + return Type(lhs) & rhs; \ + } \ + inline Type operator&(Type::flag_type lhs, \ + const Type& rhs)ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator&(Type::flag_type lhs, const Type& rhs) { \ + return rhs & lhs; \ + } \ + inline void operator&(Type::flag_type lhs, Type::mask_type rhs)ALLOW_UNUSED; \ + inline void operator&(Type::flag_type lhs, Type::mask_type rhs) {} \ + inline Type operator|(Type::flag_type lhs, Type::flag_type rhs) \ + ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator|(Type::flag_type lhs, Type::flag_type rhs) { \ + return Type(lhs) | rhs; \ + } \ + inline Type operator|(Type::flag_type lhs, const Type& rhs) \ + ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator|(Type::flag_type lhs, const Type& rhs) { \ + return rhs | lhs; \ + } \ + inline void operator|(Type::flag_type lhs, Type::mask_type rhs) \ + ALLOW_UNUSED; \ + inline void operator|(Type::flag_type lhs, Type::mask_type rhs) {} \ + inline Type operator^(Type::flag_type lhs, Type::flag_type rhs) \ + ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator^(Type::flag_type lhs, Type::flag_type rhs) { \ + return Type(lhs) ^ rhs; \ + } inline Type operator^(Type::flag_type lhs, const Type& rhs) \ + ALLOW_UNUSED WARN_UNUSED_RESULT; \ + inline Type operator^(Type::flag_type lhs, const Type& rhs) { \ + return rhs ^ lhs; \ + } inline void operator^(Type::flag_type lhs, Type::mask_type rhs) \ + ALLOW_UNUSED; \ + inline void operator^(Type::flag_type lhs, Type::mask_type rhs) {} + +} // namespace base +} // namespace v8 + +#endif // V8_BASE_FLAGS_H_ |