/// Checks if an integer fits into the given bit width.
template <unsigned N> constexpr inline bool isInt(int64_t x) {
- return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
-}
-// Template specializations to get better code for common cases.
-template <> constexpr inline bool isInt<8>(int64_t x) {
- return static_cast<int8_t>(x) == x;
-}
-template <> constexpr inline bool isInt<16>(int64_t x) {
- return static_cast<int16_t>(x) == x;
-}
-template <> constexpr inline bool isInt<32>(int64_t x) {
- return static_cast<int32_t>(x) == x;
+ if constexpr (N == 8)
+ return static_cast<int8_t>(x) == x;
+ if constexpr (N == 16)
+ return static_cast<int16_t>(x) == x;
+ if constexpr (N == 32)
+ return static_cast<int32_t>(x) == x;
+ if constexpr (N < 64)
+ return -(INT64_C(1) << (N - 1)) <= x && x < (INT64_C(1) << (N - 1));
+ (void)x; // MSVC v19.25 warns that x is unused.
+ return true;
}
/// Checks if a signed integer is an N bit number shifted left by S.
}
/// Checks if an unsigned integer fits into the given bit width.
-///
-/// This is written as two functions rather than as simply
-///
-/// return N >= 64 || X < (UINT64_C(1) << N);
-///
-/// to keep MSVC from (incorrectly) warning on isUInt<64> that we're shifting
-/// left too many places.
-template <unsigned N>
-constexpr inline std::enable_if_t<(N < 64), bool> isUInt(uint64_t X) {
+template <unsigned N> constexpr inline bool isUInt(uint64_t x) {
static_assert(N > 0, "isUInt<0> doesn't make sense");
- return X < (UINT64_C(1) << (N));
-}
-template <unsigned N>
-constexpr inline std::enable_if_t<N >= 64, bool> isUInt(uint64_t) {
+ if constexpr (N == 8)
+ return static_cast<uint8_t>(x) == x;
+ if constexpr (N == 16)
+ return static_cast<uint16_t>(x) == x;
+ if constexpr (N == 32)
+ return static_cast<uint32_t>(x) == x;
+ if constexpr (N < 64)
+ return x < (UINT64_C(1) << (N));
+ (void)x; // MSVC v19.25 warns that x is unused.
return true;
}
-// Template specializations to get better code for common cases.
-template <> constexpr inline bool isUInt<8>(uint64_t x) {
- return static_cast<uint8_t>(x) == x;
-}
-template <> constexpr inline bool isUInt<16>(uint64_t x) {
- return static_cast<uint16_t>(x) == x;
-}
-template <> constexpr inline bool isUInt<32>(uint64_t x) {
- return static_cast<uint32_t>(x) == x;
-}
-
/// Checks if a unsigned integer is an N bit number shifted left by S.
template <unsigned N, unsigned S>
constexpr inline bool isShiftedUInt(uint64_t x) {