100 lines
3.2 KiB
C++
100 lines
3.2 KiB
C++
#ifndef AL_BYTE_H
|
|
#define AL_BYTE_H
|
|
|
|
#include <cstddef>
|
|
#include <limits>
|
|
#include <type_traits>
|
|
|
|
namespace al {
|
|
|
|
/* The "canonical" way to store raw byte data. Like C++17's std::byte, it's not
|
|
* treated as a character type and does not work with arithmatic ops. Only
|
|
* bitwise ops are allowed.
|
|
*/
|
|
enum class byte : unsigned char { };
|
|
|
|
#define REQUIRES(...) typename std::enable_if<(__VA_ARGS__),bool>::type = true
|
|
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)>
|
|
inline constexpr T to_integer(al::byte b) noexcept { return T(b); }
|
|
|
|
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)>
|
|
inline constexpr al::byte operator<<(al::byte lhs, T rhs) noexcept
|
|
{ return al::byte(to_integer<unsigned int>(lhs) << rhs); }
|
|
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)>
|
|
inline constexpr al::byte operator>>(al::byte lhs, T rhs) noexcept
|
|
{ return al::byte(to_integer<unsigned int>(lhs) >> rhs); }
|
|
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)>
|
|
inline al::byte& operator<<=(al::byte &lhs, T rhs) noexcept
|
|
{ lhs = lhs << rhs; return lhs; }
|
|
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)>
|
|
inline al::byte& operator>>=(al::byte &lhs, T rhs) noexcept
|
|
{ lhs = lhs >> rhs; return lhs; }
|
|
|
|
#define AL_DECL_OP(op) \
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)> \
|
|
inline constexpr al::byte operator op (al::byte lhs, T rhs) noexcept \
|
|
{ return al::byte(to_integer<unsigned int>(lhs) op static_cast<unsigned int>(rhs)); } \
|
|
template<typename T, REQUIRES(std::is_integral<T>::value)> \
|
|
inline al::byte& operator op##= (al::byte &lhs, T rhs) noexcept \
|
|
{ lhs = lhs op rhs; return lhs; } \
|
|
inline constexpr al::byte operator op (al::byte lhs, al::byte rhs) noexcept \
|
|
{ return al::byte(lhs op to_integer<unsigned int>(rhs)); } \
|
|
inline al::byte& operator op##= (al::byte &lhs, al::byte rhs) noexcept \
|
|
{ lhs = lhs op rhs; return lhs; }
|
|
|
|
AL_DECL_OP(|)
|
|
AL_DECL_OP(&)
|
|
AL_DECL_OP(^)
|
|
|
|
#undef AL_DECL_OP
|
|
|
|
inline constexpr al::byte operator~(al::byte b) noexcept
|
|
{ return al::byte(~to_integer<unsigned int>(b)); }
|
|
|
|
|
|
template<size_t N>
|
|
class bitfield {
|
|
static constexpr size_t bits_per_byte{std::numeric_limits<unsigned char>::digits};
|
|
static constexpr size_t NumElems{(N+bits_per_byte-1) / bits_per_byte};
|
|
|
|
byte vals[NumElems]{};
|
|
|
|
public:
|
|
template<size_t b>
|
|
inline void set() noexcept
|
|
{
|
|
static_assert(b < N, "Bit index out of range");
|
|
vals[b/bits_per_byte] |= 1 << (b%bits_per_byte);
|
|
}
|
|
template<size_t b>
|
|
inline void unset() noexcept
|
|
{
|
|
static_assert(b < N, "Bit index out of range");
|
|
vals[b/bits_per_byte] &= ~(1 << (b%bits_per_byte));
|
|
}
|
|
template<size_t b>
|
|
inline bool get() const noexcept
|
|
{
|
|
static_assert(b < N, "Bit index out of range");
|
|
return (vals[b/bits_per_byte] & (1 << (b%bits_per_byte))) != byte{};
|
|
}
|
|
|
|
template<size_t b, size_t ...args, REQUIRES(sizeof...(args) > 0)>
|
|
void set() noexcept
|
|
{
|
|
set<b>();
|
|
set<args...>();
|
|
}
|
|
};
|
|
|
|
#undef REQUIRES
|
|
|
|
} // namespace al
|
|
|
|
#endif /* AL_BYTE_H */
|