tachyon::Hash Namespace Reference

Functions
constexpr uint64_t	CalculateConst (std::string_view str, uint64_t hash=Basis)
	FNV-1a hash of str, usable at compile time; hash continues an earlier hash.
uint64_t	Calculate (std::string_view str)
	FNV-1a hash of str; same result as CalculateConst.
uint64_t	CalculateBytes (const void *data, size_t len)
	FNV-1a hash of len bytes at data.
template<typename T, typename = std::enable_if_t<std::is_trivially_copyable_v<std::decay_t<T>> && !std::is_pointer_v<std::decay_t<T>> && !std::is_same_v<std::decay_t<T>, std::string_view>>>
uint64_t	Calculate (const T &value)
	FNV-1a hash of a trivially-copyable value's bytes, padding included.
constexpr uint64_t	Combine (uint64_t a, uint64_t b)
	Order-dependent combine; repeated values don't cancel out.
template<typename... Args>
constexpr uint64_t	Combine (const Args &... args)
	Combines the Calculate hashes of args, in order.

Variables
constexpr uint64_t	Basis = 14695981039346656037ULL
	FNV-1a 64-bit offset basis (Prime is the FNV-1a prime).
constexpr uint64_t	Prime = 1099511628211ULL

Function Documentation

CalculateConst()

uint64_t tachyon::Hash::CalculateConst ( std::string_view str, uint64_t hash = Basis )

constexpr

FNV-1a hash of str, usable at compile time; hash continues an earlier hash.

Calculate() [1/2]

uint64_t tachyon::Hash::Calculate ( std::string_view str )

inline

FNV-1a hash of str; same result as CalculateConst.

CalculateBytes()

uint64_t tachyon::Hash::CalculateBytes ( const void * data, size_t len )

inline

FNV-1a hash of len bytes at data.

Calculate() [2/2]

template<typename T, typename = std::enable_if_t<std::is_trivially_copyable_v<std::decay_t<T>> && !std::is_pointer_v<std::decay_t<T>> && !std::is_same_v<std::decay_t<T>, std::string_view>>>

uint64_t tachyon::Hash::Calculate ( const T & value )

inline

FNV-1a hash of a trivially-copyable value's bytes, padding included.

Pointers are rejected: hashing one hashes the address, not the object.

Combine() [1/2]

uint64_t tachyon::Hash::Combine ( uint64_t a, uint64_t b )

inlineconstexpr

Order-dependent combine; repeated values don't cancel out.

Combine() [2/2]

template<typename... Args>

uint64_t tachyon::Hash::Combine ( const Args &... args )

inlineconstexpr

Combines the Calculate hashes of args, in order.

Variable Documentation

Basis

uint64_t tachyon::Hash::Basis = 14695981039346656037ULL

constexpr

FNV-1a 64-bit offset basis (Prime is the FNV-1a prime).

Prime

uint64_t tachyon::Hash::Prime = 1099511628211ULL

constexpr