utils Namespace Reference

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Table of Contents

• Detailed Description
• Namespaces
• Classes
• Typedefs
• Enumerations
• Functions
• Variables
• Typedef Documentation
• DecayToStringView
• NonLoggable
• Enumeration Type Documentation
• StrongTypedefOps
• Function Documentation
• AbortWithStacktrace()
• AnyCast() [1/5]
• AnyCast() [2/5]
• AnyCast() [3/5]
• AnyCast() [4/5]
• AnyCast() [5/5]
• as_bytes()
• as_writable_bytes()
• AsContainer()
• BaseRunOptions()
• CheckedFind()
• ContainsIf()
• DaemonMain() [1/3]
• DaemonMain() [2/3]
• DaemonMain() [3/3]
• enumerate()
• Erase()
• EraseIf()
• ExtractTimestampFromUuidV7()
• FindOptional()
• FindOrDefault() [1/2]
• FindOrDefault() [2/2]
• FindOrNullptr()
• ForEachIndex()
• FromString()
• GenerateFixedArray()
• GetCurrentThreadName()
• GetIf() [1/2]
• GetIf() [2/2]
• GetNearestString()
• GetUserverIdentifier()
• GetUserverVcsRevision()
• GetUserverVersion()
• hash_value()
• IsMainThread()
• IsStrongTypedefLoggable()
• LogErrorAndThrow()
• make_intrusive_ptr()
• MakeCheckedPtr()
• MakeLazyCachePtr()
• MakeSharedReadable()
• MakeSharedRef()
• MakeTrivialBiMap()
• MakeTrivialSet()
• MakeUniqueRef()
• numeric_cast()
• Example usage:
• operator!=() [1/8]
• operator!=() [2/8]
• operator!=() [3/8]
• operator!=() [4/8]
• operator!=() [5/8]
• operator!=() [6/8]
• operator!=() [7/8]
• operator!=() [8/8]
• operator&() [1/3]
• operator&() [2/3]
• operator&() [3/3]
• operator<<() [1/3]
• operator<<() [2/3]
• operator<<() [3/3]
• operator==() [1/10]
• operator==() [2/10]
• operator==() [3/10]
• operator==() [4/10]
• operator==() [5/10]
• operator==() [6/10]
• operator==() [7/10]
• operator==() [8/10]
• operator==() [9/10]
• operator==() [10/10]
• operator|() [1/3]
• operator|() [2/3]
• operator|() [3/3]
• OptionalTransform()
• Parse() [1/5]
• Parse() [2/5]
• Parse() [3/5]
• Parse() [4/5]
• Parse() [5/5]
• ParseFromValueString()
• PrintTo()
• ProjectedFind()
• ProjectedInsertOrAssign()
• Rand()
• RandRange() [1/2]
• RandRange() [2/2]
• regex_match()
• regex_replace() [1/2]
• regex_replace() [2/2]
• regex_search()
• Serialize() [1/5]
• Serialize() [2/5]
• Serialize() [3/5]
• Serialize() [4/5]
• Serialize() [5/5]
• SetCurrentThreadIdleScheduling()
• SetCurrentThreadLowPriorityScheduling()
• SetCurrentThreadName()
• Shuffle()
• StrCat()
• StringToBytesPerSecond()
• StringToDuration()
• StrongCast() [1/2]
• StrongCast() [2/2]
• SuggestNearestName()
• ToLongLong()
• ToString() [1/3]
• ToString() [2/3]
• ToString() [3/3]
• UnderlyingValue() [1/3]
• UnderlyingValue() [2/3]
• UnderlyingValue() [3/3]
• Visit() [1/3]
• Visit() [2/3]
• Visit() [3/3]
• WithConstexprIndex()
• WithDefaultRandom()
• Usage example
• WithSafeHash() [1/8]
• WithSafeHash() [2/8]
• WithSafeHash() [3/8]
• WithSafeHash() [4/8]
• WithSafeHash() [5/8]
• WithSafeHash() [6/8]
• WithSafeHash() [7/8]
• WithSafeHash() [8/8]
• WriteToStream() [1/2]
• WriteToStream() [2/2]
• Variable Documentation
• kDefaultDictDefaultName
• kStrictMatch

Detailed Description

Utilities.

Namespaces
namespace	datetime
	Date and time utilities.
namespace	generators
	Generators.
namespace	ip
	IP address and utilities.
namespace	log
	Algorithms to aid logging.
namespace	text
	Text utilities.

Classes
class	AnyMovable
	Replacement for std::any that is not copyable. It allows to store non-copyable and even non-movable types. More...
class	AnyStorage
	map-like heterogeneous data storage More...
class	AnyStorageDataTag
class	AtomicFlags
	Wrapper to extend enum with atomic flags interface. More...
class	bad_expected_access
class	BadAnyMovableCast
	The exception that is thrown when AnyCast fails. More...
class	Box
	Remote storage for a single item. Implemented as a unique pointer that is never null, except when moved from. More...
struct	CachedHash
	Holds the key and its hash for faster comparisons and hashing. More...
class	CachedHashKeyEqual
	Compares utils::CachedHash only by keys. More...
class	CachedHashKeyEqual< Equal, std::false_type >
class	CheckedPtr
	Utility template for returning a pointer to an object that is owned by someone else; throws std::runtime_error if nullptr is stored. More...
class	CheckedPtr< T & >
class	CpuRelax
class	CurrentThreadNameGuard
	RAII helper to run some code with a temporary current thread name. More...
class	DefaultDict
	Dictionary that for missing keys falls back to a default value stored by key utils::kDefaultDictDefaultName. More...
class	expected
	For holding a value or an error. More...
class	FastPimpl
	Implements pimpl idiom without dynamic memory allocation. More...
class	FastScopeGuard
	a helper class to perform actions on scope exit More...
class	FilterBloom
	Space-efficient probabilistic data structure. More...
class	FixedArray
	A fixed-size array with the size determined at runtime. More...
class	Flags
	Wrapper to extend enum with flags interface. More...
struct	HashSeed
	The seed structure used by underlying hashing implementation. More...
class	InvariantError
	Exception that is thrown on UINVARIANT violation. More...
class	LazyPrvalue
	Can be used with various emplace functions to allow in-place constructing a non-movable value using a callable. More...
class	LazySharedPtr
	A lazy wrapper around utils::SharedReadablePtr that fetches the data on first access. More...
class	MacaddrBase
	Base class for Macaddr/Macaddr8. More...
class	match_results
	A drop-in replacement for std::match_results without huge includes and with better performance characteristics. Represents capturing groups of a single match result. More...
class	NotNull
	Restricts a pointer or smart pointer to only hold non-null values. More...
class	OptionalRef
	Class that behaves as a nullable reference. Main difference from the pointer - value comparison of pointed values. More...
struct	Overloaded
	Utility to define std::variant visitors in a simple way. More...
class	PeriodicTask
	Task that periodically runs a user callback. Callback is started after the previous callback execution is finished every period + A - B, where: More...
class	RandomBase
	Virtualized standard UniformRandomBitGenerator concept, for use with random number distributions. More...
struct	Re2Replacement
	Replacement string with substitution support. More...
class	regex
	A drop-in replacement for std::regex without huge includes and with better performance characteristics. More...
class	RegexError
	Thrown from constructors of utils::regex with an invalid pattern. More...
class	ResultStore
class	ResultStore< void >
class	RetryBudget
struct	RetryBudgetSettings
class	ScopeGuard
	a helper class to perform actions on scope exit More...
class	ScopeTimePause
	Utility to easily pause ScopeTime, e.g. when yielding. More...
class	SharedReadablePtr
	std::shared_ptr<const T> wrapper that makes sure that the pointer is stored before dereferencing. Protects from dangling references. More...
class	SlidingInterval
	Sliding interval of values that provides functions to compute average, min and max values from the last window_size values of interval. More...
class	SmallString
	An alternative to std::string with a custom SSO (small string optimization) container size. Unlike std::string, SmallString is not null-terminated thus it has no c_str(), data() returns a not null-terminated buffer. More...
class	span
	A polyfill for std::span from C++20. More...
class	StrCaseHash
	Case sensitive ASCII hashing functor. More...
class	StreamingCpuRelax
class	StrIcaseCompareThreeWay
	Case insensitive ASCII 3-way comparison functor. More...
class	StrIcaseEqual
	Case insensitive ASCII equality comparison functor. More...
class	StrIcaseHash
	Case insensitive ASCII hashing functor. More...
class	StrIcaseLess
	Case insensitive ASCII less comparison functor. More...
class	StringLiteral
	Non-empty string view to a compile time known null terminated char array that lives for the lifetime of program, as per [lex.string]; a drop-in replacement for static const std::string kVar = "value" and constexpr std::string_view kVar = "value". More...
class	StrongTypedef
	Strong typedef for a type T. More...
class	SwappingSmart
class	TokenBucket
class	TracefulException
	Exception that remembers the backtrace at the point of its construction. More...
class	TracefulExceptionBase
	Base class implementing backtrace storage and message builder, published only for documentation purposes, please inherit from utils::TracefulException instead. More...
class	TrivialBiMap
	Bidirectional unordered map for trivial types, including string literals; could be efficiently used as a unordered non-bidirectional map. More...
class	TrivialSet
	Unordered set for trivial types, including string literals. More...
class	unexpected
class	zstring_view
	Non-empty string view type that guarantees null-termination and has a c_str() member function. More...

Typedefs
template<typename U >
using	SharedRef = NotNull< std::shared_ptr< U > >
	A std::shared_ptr that is guaranteed to be not-null.
template<typename U >
using	UniqueRef = NotNull< std::unique_ptr< U > >
	A std::unique_ptr that is guaranteed to be not-null.
template<class Tag , class T >
using	NonLoggable = StrongTypedef< Tag, T, StrongTypedefOps::kCompareStrong|StrongTypedefOps::kNonLoggable >
template<typename... T>
using	void_t = std::void_t< T... >
	std::void_t implementation with workarounds for compiler bugs
template<class T >
using	DecayToStringView = std::conditional_t< std::is_same_v< T, StringLiteral >||std::is_same_v< T, zstring_view >, std::string_view, T >
	Decays utils::StringLiteral and utils::zstring_view to a more generic std::string_view type.
using	Macaddr = MacaddrBase< 6 >
	48-bit MAC address
using	Macaddr8 = MacaddrBase< 8 >
	64-bit MAC address
template<typename Value , auto Projection, typename Hash = void, typename Equal = std::equal_to<>, typename Allocator = std::allocator<Value>>
using	ProjectedUnorderedSet = utils::impl::TransparentSet< Value, impl::projected_set::Hash< Value, Projection, Hash >, impl::projected_set::Compare< Value, Projection, Equal >, Allocator >
	A std::unordered_set that compares its elements (of type Value) based on their Projection. It allows to create, essentially, an equivalent of std::unordered_map where keys are stored inside values.
template<typename Value , auto Projection, typename Compare = std::less<>, typename Allocator = std::allocator<Value>>
using	ProjectedSet = std::set< Value, impl::projected_set::Compare< Value, Projection, Compare >, Allocator >
	Same as utils::ProjectedUnorderedSet, but for std::set.

Enumerations
enum class	StrongTypedefOps {   kNoCompare = 0 ,   kCompareStrong = 1 ,   kCompareTransparentOnly = 2 ,   kCompareTransparent = 3 ,   kNonLoggable = 4 }
enum class	BytesPerSecond : long long
	Data type that represents bytes per second unit. More...

Functions
template<typename U , typename... Args>
SharedRef< U >	MakeSharedRef (Args &&... args)
	An equivalent of std::make_shared for SharedRef.
template<typename U , typename... Args>
UniqueRef< U >	MakeUniqueRef (Args &&... args)
	An equivalent of std::make_unique for UniqueRef.
template<typename ValueType >
ValueType *	AnyCast (AnyMovable *operand) noexcept
template<typename ValueType >
const ValueType *	AnyCast (const AnyMovable *operand) noexcept
template<typename ValueType >
ValueType	AnyCast (AnyMovable &operand)
template<typename ValueType >
ValueType	AnyCast (const AnyMovable &operand)
template<typename ValueType >
ValueType	AnyCast (AnyMovable &&operand)
void	AbortWithStacktrace (std::string_view message) noexcept
	Function that prints the stacktrace with message and aborts the program execution.
template<typename Enum >
constexpr Flags< Enum >	operator| (Enum, Flags< Enum >)
template<typename Enum >
constexpr Flags< Enum >	operator& (Enum, Flags< Enum >)
template<typename Enum >
constexpr bool	operator== (Enum, Flags< Enum >)
template<typename Enum >
constexpr bool	operator!= (Enum, Flags< Enum >)
template<typename Enum >
Flags< Enum >	operator| (Enum, const AtomicFlags< Enum > &)
template<typename Enum >
Flags< Enum >	operator& (Enum, const AtomicFlags< Enum > &)
template<typename Enum >
bool	operator== (Enum, const AtomicFlags< Enum > &)
template<typename Enum >
bool	operator!= (Enum, const AtomicFlags< Enum > &)
constexpr bool	operator& (StrongTypedefOps op, StrongTypedefOps mask) noexcept
constexpr auto	operator| (StrongTypedefOps op1, StrongTypedefOps op2) noexcept
template<class Tag , class T , StrongTypedefOps Ops>
std::ostream &	operator<< (std::ostream &os, const StrongTypedef< Tag, T, Ops > &v)
	Ostreams and Logging.
template<class Tag , class T , StrongTypedefOps Ops>
logging::LogHelper &	operator<< (logging::LogHelper &os, const StrongTypedef< Tag, T, Ops > &v)
template<class Tag , class T , StrongTypedefOps Ops>
constexpr decltype(auto)	UnderlyingValue (const StrongTypedef< Tag, T, Ops > &v) noexcept
template<class Tag , class T , StrongTypedefOps Ops>
constexpr T	UnderlyingValue (StrongTypedef< Tag, T, Ops > &&v) noexcept
constexpr bool	IsStrongTypedefLoggable (StrongTypedefOps Ops)
template<typename T , typename Value >
std::enable_if_t< formats::common::kIsFormatValue< Value > &&IsStrongTypedef< T >{}, T >	Parse (const Value &source, formats::parse::To< T >)
template<typename T , typename Value >
std::enable_if_t< IsStrongTypedef< T >{}, Value >	Serialize (const T &object, formats::serialize::To< Value >)
template<typename T , typename StringBuilder >
std::enable_if_t< IsStrongTypedef< T >{}>	WriteToStream (const T &object, StringBuilder &sw)
template<typename Tag , StrongTypedefOps Ops>
std::string	ToString (const StrongTypedef< Tag, std::string, Ops > &object)
template<typename Tag , typename T , StrongTypedefOps Ops, std::enable_if_t< meta::kIsInteger< T >, bool > = true>
std::string	ToString (const StrongTypedef< Tag, T, Ops > &object)
template<typename Target , typename Tag , typename T , StrongTypedefOps Ops, typename Enable >
constexpr Target	StrongCast (const StrongTypedef< Tag, T, Ops, Enable > &src)
template<typename Target , typename Tag , typename T , StrongTypedefOps Ops, typename Enable >
constexpr Target	StrongCast (StrongTypedef< Tag, T, Ops, Enable > &&src)
template<class Tag , class T , StrongTypedefOps Ops>
std::size_t	hash_value (const StrongTypedef< Tag, T, Ops > &v)
template<class Tag , class T , StrongTypedefOps Ops>
void	PrintTo (const StrongTypedef< Tag, T, Ops > &v, std::ostream *os)
	gtest formatter for utils::StrongTypedef
template<class Value >
Value	Serialize (StringLiteral literal, formats::serialize::To< Value >)
template<typename T , typename Func >
T	AtomicUpdate (std::atomic< T > &atomic, Func updater)
	Atomically performs the operation of updater on atomic
template<typename T >
T	AtomicMin (std::atomic< T > &atomic, T value)
	Concurrently safe sets atomic to a value if value is less.
template<typename T >
T	AtomicMax (std::atomic< T > &atomic, T value)
	Concurrently safe sets atomic to a value if value is greater.
std::chrono::milliseconds	StringToDuration (std::string_view data)
	Converts strings like "10s", "5d", "1h" to durations.
template<class T , std::enable_if_t< std::is_enum_v< T >, int > = 0>
constexpr auto	UnderlyingValue (T v) noexcept
	Function that extracts integral value from enum or StrongTypedef.
template<class Value >
Value	Serialize (zstring_view view, formats::serialize::To< Value >)
template<class GeneratorFunc >
auto	GenerateFixedArray (std::size_t size, GeneratorFunc &&generator)
	Applies generator to indices in the range [0, size), storing the results in a new utils::FixedArray. The generator is guaranteed to be invoked in the first-to-last order.
template<typename BuilderFunc >
	TrivialBiMap (BuilderFunc) -> TrivialBiMap< BuilderFunc >
template<typename BuilderFunc >
	TrivialSet (BuilderFunc) -> TrivialSet< BuilderFunc >
template<typename ExceptionType = void, typename Value , typename BuilderFunc >
auto	ParseFromValueString (const Value &value, TrivialBiMap< BuilderFunc > map)
	Parses and returns whatever is specified by map from a formats::json::Value or another format's Value.
template<const auto & Keys, const auto & Values>
constexpr auto	MakeTrivialBiMap ()
	Zips two global constexpr arrays into an utils::TrivialBiMap.
template<const auto & Values>
constexpr auto	MakeTrivialSet ()
template<class T , class U >
constexpr bool	operator== (OptionalRef< T > lhs, OptionalRef< U > rhs) noexcept
template<class T , class U >
constexpr bool	operator!= (OptionalRef< T > lhs, OptionalRef< U > rhs) noexcept
boost::program_options::options_description	BaseRunOptions ()
int	DaemonMain (int argc, const char *const argv[], const components::ComponentList &components_list)
int	DaemonMain (const boost::program_options::variables_map &vm, const components::ComponentList &components_list)
int	DaemonMain (const components::InMemoryConfig &config, const components::ComponentList &components_list)
template<typename ResultString = std::string, typename... Strings>
ResultString	StrCat (const Strings &... strings)
	Concatenates multiple std::string_view-convertible items.
template<typename Container , typename Key >
auto *	FindOrNullptr (Container &container, const Key &key)
	Returns nullptr if no key in associative container, otherwise returns pointer to value.
template<typename Container , typename Key , typename Default >
auto	FindOrDefault (Container &container, const Key &key, Default &&def)
	Returns default value if no key in associative container, otherwise returns a copy of the stored value.
template<typename Container , typename Key >
auto	FindOrDefault (Container &container, const Key &key)
	Returns default value if no key in associative container, otherwise returns a copy of the stored value.
template<typename Container , typename Key >
auto	FindOptional (Container &container, const Key &key)
	Returns std::nullopt if no key in associative container, otherwise returns std::optional with a copy of value.
template<typename Container , typename Key >
auto	CheckedFind (Container &container, const Key &key)
	Searches a map for an element and return a checked pointer to the found element.
template<typename ToContainer , typename FromContainer >
ToContainer	AsContainer (FromContainer &&container)
	Converts one container type to another.
template<typename Container , typename Pred >
auto	EraseIf (Container &container, Pred pred)
	Erased elements and returns number of deleted elements.
template<typename Container , typename T >
size_t	Erase (Container &container, const T &elem)
	Erased elements and returns number of deleted elements.
template<typename Container , typename Pred >
bool	ContainsIf (const Container &container, Pred pred)
	returns true if there is an element in container which satisfies the predicate
template<typename T = std::runtime_error>
void	LogErrorAndThrow (const std::string &error_message)
	Logs error_message and throws an exception ith that message.
template<typename T >
constexpr CheckedPtr< T >	MakeCheckedPtr (T *ptr) noexcept
boost::uuids::uuid	BoostUuidFromString (std::string_view str)
	Parse string into boost::uuids::uuid.
std::string	ToString (const boost::uuids::uuid &)
	Serialize boost::uuids::uuid to string.
std::chrono::system_clock::time_point	ExtractTimestampFromUuidV7 (boost::uuids::uuid uuid)
	Extracts timestamp from UUIDv7.
template<typename Value , typename T >
Box< T >	Parse (const Value &value, formats::parse::To< Box< T > >)
template<typename Value , typename T >
Value	Serialize (const Box< T > &value, formats::serialize::To< Value >)
template<typename StringBuilder , typename T >
void	WriteToStream (const Box< T > &value, StringBuilder &sw)
template<typename T >
logging::LogHelper &	operator<< (logging::LogHelper &lh, const Box< T > &box)
constexpr long long	ToLongLong (BytesPerSecond x)
constexpr bool	operator== (BytesPerSecond lhs, BytesPerSecond rhs)
constexpr bool	operator!= (BytesPerSecond lhs, BytesPerSecond rhs)
BytesPerSecond	StringToBytesPerSecond (const std::string &data)
template<class Value >
BytesPerSecond	Parse (const Value &v, formats::parse::To< BytesPerSecond >)
template<class T >
constexpr bool	operator== (const CachedHash< T > &x, const CachedHash< T > &y)
	Compares utils::CachedHash by hash first and then by keys.
template<class T >
constexpr bool	operator!= (const CachedHash< T > &x, const CachedHash< T > &y)
	Compares utils::CachedHash by hash first and then by keys.
template<std::size_t Count, typename Func >
void	ForEachIndex (Func func)
template<std::size_t Count, typename Func >
void	WithConstexprIndex (std::size_t runtime_index, Func func)
	Calls func with runtime_index wrapped in std::integral_constant.
template<typename Value , typename T >
std::enable_if_t< formats::common::kIsFormatValue< Value >, DefaultDict< T > >	Parse (const Value &value, formats::parse::To< DefaultDict< T > >)
std::size_t	GetLevenshteinDistance (std::string_view view1, std::string_view view2)
	Returns the Levenshtein distance between two strings.
std::size_t	GetDamerauLevenshteinDistance (std::string_view view1, std::string_view view2)
	Returns the Damerau-Levenshtein distance between two strings.
template<typename StringViews , typename DistanceFunc = std::size_t (*)(std::string_view, std::string_view)>
std::optional< std::string_view >	GetNearestString (const StringViews &strings, std::string_view key, std::size_t max_distance, DistanceFunc distance_func=&utils::GetLevenshteinDistance)
	Returns a nearest string for a key from a bunch of strings.
template<typename StringViews >
std::string	SuggestNearestName (const StringViews &strings, std::string_view key)
	Returns a suggestion for a key.
template<typename Container >
constexpr auto	enumerate (Container &&iterable)
	Implementation of python-style enumerate function for range-for loops.
template<class E >
	unexpected (E) -> unexpected< E >
template<typename T , typename StringType , typename = std::enable_if_t<std::is_convertible_v<StringType, std::string_view>>>
T	FromString (const StringType &str)
	Extract the number contained in the string. No space characters or other extra characters allowed. Supported types:
std::int64_t	FromHexString (std::string_view str)
template<typename Leaf >
constexpr auto *	GetIf (Leaf &&leaf)
template<typename Root , typename Head , typename... Tail>
constexpr auto *	GetIf (Root &&root, Head &&head, Tail &&... tail)
	Dereferences a chain of indirections and compositions, returns nullptr if one of the chain elements is not set.
std::string	MacaddrToString (Macaddr macaddr)
	Get 48-bit MAC address as a string in "xx:xx:.." format.
std::string	Macaddr8ToString (Macaddr8 macaddr)
	Get 64-bit MAC address as a string in "xx:xx:.." format.
Macaddr	MacaddrFromString (const std::string &str)
	Get 48-bit MAC address from std::string.
Macaddr8	Macaddr8FromString (const std::string &str)
	Get 64-bit MAC address from std::string.
template<class Target , class... Args>
boost::intrusive_ptr< Target >	make_intrusive_ptr (Args &&... args)
	Factory function for boost::intrusive_ptr, like std::make_unique.
template<typename To , typename From >
constexpr To	numeric_cast (From input)
template<class T >
std::string	ToString (const std::optional< T > &from)
	Converts std::optional to a string, empty value represented as "--".
template<typename T , typename Func >
auto	OptionalTransform (T &&opt, Func func) -> std::optional< decltype(std::move(func)(*std::forward< T >(opt)))>
	A polyfill for C++23 monadic operations for std::optional.
template<class... Ts>
	Overloaded (Ts...) -> Overloaded< Ts... >
template<class... Args, class... Ts>
constexpr decltype(auto)	Visit (const std::variant< Args... > &var, Ts &&... ts)
template<class... Args, class... Ts>
constexpr decltype(auto)	Visit (std::variant< Args... > &var, Ts &&... ts)
template<class... Args, class... Ts>
constexpr decltype(auto)	Visit (std::variant< Args... > &&var, Ts &&... ts)
template<typename Container , typename Value >
void	ProjectedInsertOrAssign (Container &set, Value &&value)
	An equivalent of std::unordered_map::insert_or_assign for utils::ProjectedUnorderedSet and utils::ProjectedSet.
template<typename Container , typename Key >
auto	ProjectedFind (Container &set, const Key &key)
	An equivalent of std::unordered_map::find for utils::ProjectedUnorderedSet and utils::ProjectedSet.
template<typename Func >
decltype(auto)	WithDefaultRandom (Func &&func)
	Calls func with a thread-local UniformRandomBitGenerator (specifically of type utils::RandomBase).
template<typename T >
T	RandRange (T from_inclusive, T to_exclusive)
	Generates a random number in range [from, to)
template<typename T >
T	RandRange (T to_exclusive)
	Generates a random number in range [0, to)
template<typename Container >
void	Shuffle (Container &container)
	Shuffles the elements within the container.
std::uint32_t	Rand ()
	Generate a random number in the whole uint32_t range.
bool	regex_match (std::string_view str, const regex &pattern)
	Determines whether the regular expression matches the entire target character sequence.
bool	regex_match (std::string_view str, match_results &m, const regex &pattern)
	Returns true if the specified regular expression matches the whole of the input. Fills in what matched in m.
bool	regex_search (std::string_view str, const regex &pattern)
	Determines whether the regular expression matches anywhere in the target character sequence.
bool	regex_search (std::string_view str, match_results &m, const regex &pattern)
	Determines whether the regular expression matches anywhere in the target character sequence. Fills in what matched in m.
std::string	regex_replace (std::string_view str, const regex &pattern, std::string_view repl)
	Create a new string where all regular expression matches replaced with repl.
std::string	regex_replace (std::string_view str, const regex &pattern, Re2Replacement repl)
void	RegisterResource (std::string_view name, std::string_view value)
std::string	FindResource (std::string_view name)
template<typename T >
bool	operator== (const SharedReadablePtr< T > &ptr, std::nullptr_t)
template<typename T >
bool	operator== (std::nullptr_t, const SharedReadablePtr< T > &ptr)
template<typename T >
bool	operator!= (const SharedReadablePtr< T > &ptr, std::nullptr_t)
template<typename T >
bool	operator!= (std::nullptr_t, const SharedReadablePtr< T > &ptr)
template<typename T , typename... Args>
SharedReadablePtr< T >	MakeSharedReadable (Args &&... args)
template<std::size_t N>
bool	operator== (const SmallString< N > &str, std::string_view sv)
template<std::size_t N>
bool	operator== (std::string_view sv, const SmallString< N > &str)
template<std::size_t N>
bool	operator== (const SmallString< N > &str1, const SmallString< N > &str2)
template<std::size_t N>
bool	operator!= (const SmallString< N > &str1, const SmallString< N > &str2)
template<typename Value , std::size_t N>
Value	Serialize (const SmallString< N > &value, formats::serialize::To< Value >)
template<typename Value , std::size_t N>
SmallString< N >	Parse (const Value &value, formats::parse::To< SmallString< N > >)
template<typename Container >
	span (Container &&cont) -> span< std::remove_reference_t< decltype(*std::begin(cont))> >
template<typename T >
span< const std::byte >	as_bytes (span< T > s) noexcept
	A polyfill for std::as_bytes from C++20.
template<typename T , typename = std::enable_if_t<!std::is_const_v<T>>>
span< std::byte >	as_writable_bytes (span< T > s) noexcept
	A polyfill for std::as_writable_bytes from C++20.
template<typename Key , typename Value >
auto	WithSafeHash (const std::unordered_map< Key, Value > &map)
	Converts an unordered [multi-]map or set with the default hash to a map with utils::StrCaseHash. This might be useful when converting guaranteed-to-be-safe data to a common operating format.
template<typename Key , typename Value >
auto	WithSafeHash (std::unordered_map< Key, Value > &&map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key , typename Value >
auto	WithSafeHash (const std::unordered_multimap< Key, Value > &map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key , typename Value >
auto	WithSafeHash (std::unordered_multimap< Key, Value > &&map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key >
auto	WithSafeHash (const std::unordered_set< Key > &map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key >
auto	WithSafeHash (std::unordered_set< Key > &&map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key >
auto	WithSafeHash (const std::unordered_multiset< Key > &map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename Key >
auto	WithSafeHash (std::unordered_multiset< Key > &&map)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
std::string	strerror (int return_code)
	MT-safe version of POSIX function strerror
std::string	strsignal (int signal_num)
	MT-safe version of POSIX function strsignal
std::string	GetCurrentThreadName ()
	Get the name of the current thread.
void	SetCurrentThreadName (std::string_view name)
	Set the name of the current thread.
bool	IsMainThread () noexcept
void	SetCurrentThreadIdleScheduling ()
	Set priority of the OS thread to IDLE (the lowest one)
void	SetCurrentThreadLowPriorityScheduling ()
	Set priority of the OS thread to low (but not the lowest one)
template<typename Function , typename... Args>
auto	Async (std::string name, Function &&f, Args &&... args)
	Starts an asynchronous task.
template<typename Function , typename... Args>
auto	Async (engine::TaskProcessor &task_processor, std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	CriticalAsync (engine::TaskProcessor &task_processor, std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedCriticalAsync (engine::TaskProcessor &task_processor, std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedAsync (engine::TaskProcessor &task_processor, std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	Async (engine::TaskProcessor &task_processor, std::string name, engine::Deadline deadline, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedAsync (engine::TaskProcessor &task_processor, std::string name, engine::Deadline deadline, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	CriticalAsync (std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedCriticalAsync (std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedAsync (std::string name, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	Async (std::string name, engine::Deadline deadline, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	SharedAsync (std::string name, engine::Deadline deadline, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	AsyncBackground (std::string name, engine::TaskProcessor &task_processor, Function &&f, Args &&... args)
template<typename Function , typename... Args>
auto	CriticalAsyncBackground (std::string name, engine::TaskProcessor &task_processor, Function &&f, Args &&... args)
template<typename Cache >
LazySharedPtr< typename Cache::DataType >	MakeLazyCachePtr (Cache &cache)
	Make a lazy pointer to the data of a cache.
RetryBudgetSettings	Parse (const formats::json::Value &elem, formats::parse::To< RetryBudgetSettings >)
RetryBudgetSettings	Parse (const yaml_config::Value &elem, formats::parse::To< RetryBudgetSettings >)
const char *	GetUserverVersion () noexcept
const char *	GetUserverVcsRevision () noexcept
const char *	GetUserverIdentifier () noexcept

Variables
constexpr bool	kStrictMatch = true
	Helper constant to use with FastPimpl.
constexpr std::string_view	kDefaultDictDefaultName = "__default__"
	Name of the key with default value for utils::DefaultDict.

Typedef Documentation

DecayToStringView

template<class T >

using utils::DecayToStringView = typedef std::conditional_t<std::is_same_v<T, StringLiteral> || std::is_same_v<T, zstring_view>, std::string_view, T>

Decays utils::StringLiteral and utils::zstring_view to a more generic std::string_view type.

Definition at line 633 of file trivial_map.hpp.

NonLoggable

template<class Tag , class T >

using utils::NonLoggable = typedef StrongTypedef<Tag, T, StrongTypedefOps::kCompareStrong | StrongTypedefOps::kNonLoggable>

A StrongTypedef for data that MUST NOT be logged or outputted in some other way. Also prevents the data from appearing in backtrace prints of debugger.

#include <userver/storages/secdist/provider_component.hpp>
#include <userver/storages/secdist/secdist.hpp>
 
#include <userver/crypto/algorithm.hpp>
#include <userver/formats/parse/common_containers.hpp>
#include <userver/utils/algo.hpp>
#include <userver/utils/strong_typedef.hpp>
 
class UserPasswords {
public:
    using Password = utils::NonLoggable<class PasswordTag, std::string>;
 
    UserPasswords(const formats::json::Value& doc)
        : user_passwords_(doc["user-passwords"].As<std::optional<Storage>>()) {}
 
    bool IsMatching(const std::string& user, const Password& password) const {
        if (!user_passwords_.has_value()) {
            throw std::runtime_error(
                "User passwords storage is missing. Field 'user-passwords' was "
                "missing in json."
            );
        }
 
        const auto* ptr = utils::FindOrNullptr(user_passwords_.value(), user);
        return ptr && crypto::algorithm::AreStringsEqualConstTime(ptr->GetUnderlying(), password.GetUnderlying());
    }
 
private:
    using Storage = std::unordered_map<std::string, Password>;
    std::optional<Storage> user_passwords_;
};

Definition at line 426 of file strong_typedef.hpp.

Enumeration Type Documentation

StrongTypedefOps

enum class utils::StrongTypedefOps

strong

Enumerator
kCompareStrong	Forbid all comparisons for StrongTypedef.
kCompareTransparentOnly	Allow comparing two StrongTypedef<Tag, T>
kCompareTransparent	Allow comparing StrongTypedef<Tag, T> and T.
kNonLoggable	Allow both of the above.

Definition at line 38 of file strong_typedef.hpp.

Function Documentation

AbortWithStacktrace()

void utils::AbortWithStacktrace ( std::string_view  message )

noexcept

Function that prints the stacktrace with message and aborts the program execution.

Mostly useful for placing in dead code branches or in 'should-never-happen-and-theres-no-way-to-restore' places.

AnyCast() [1/5]

template<typename ValueType >

ValueType utils::AnyCast

(

AnyMovable &&

operand

)

Note

Cast to a reference type to avoid extra moves

Exceptions

BadAnyMovableCast

if type of the data stored in operand does not match ValueType

Definition at line 218 of file any_movable.hpp.

AnyCast() [2/5]

template<typename ValueType >

ValueType utils::AnyCast

(

AnyMovable &

operand

)

Note

Cast to a reference type to avoid extra copies

Exceptions

BadAnyMovableCast

if type of the data stored in operand does not match ValueType

Definition at line 200 of file any_movable.hpp.

AnyCast() [3/5]

template<typename ValueType >

ValueType * utils::AnyCast ( AnyMovable *  operand )

noexcept

Returns

nullptr if operand is nullptr or type of the data stored in operand does not match ValueType

Definition at line 188 of file any_movable.hpp.

AnyCast() [4/5]

template<typename ValueType >

ValueType utils::AnyCast

(

const AnyMovable &

operand

)

Note

Cast to a reference type to avoid extra copies

Exceptions

BadAnyMovableCast

if type of the data stored in operand does not match ValueType

Definition at line 210 of file any_movable.hpp.

AnyCast() [5/5]

template<typename ValueType >

const ValueType * utils::AnyCast ( const AnyMovable *  operand )

noexcept

Returns

nullptr if operand is nullptr or type of the data stored in operand does not match ValueType

Definition at line 193 of file any_movable.hpp.

as_bytes()

template<typename T >

span< const std::byte > utils::as_bytes ( span< T >  s )

noexcept

A polyfill for std::as_bytes from C++20.

Definition at line 120 of file span.hpp.

as_writable_bytes()

template<typename T , typename = std::enable_if_t<!std::is_const_v<T>>>

span< std::byte > utils::as_writable_bytes ( span< T >  s )

noexcept

A polyfill for std::as_writable_bytes from C++20.

Definition at line 127 of file span.hpp.

AsContainer()

template<typename ToContainer , typename FromContainer >

ToContainer utils::AsContainer

(

FromContainer &&

container

)

Converts one container type to another.

Definition at line 92 of file algo.hpp.

BaseRunOptions()

boost::program_options::options_description utils::BaseRunOptions

(

)

Returns

default options of DaemonMain

List of options:

• –help - show all command line arguments
• –config CONFIG - path to config.yaml
• –config_vars CONFIG_VARS - path to config_vars.yaml
• –config_vars_override CONFIG_VARS - path to config_vars.override.yaml
• –print-config-schema - print config.yaml YAML Schema
• –print-dynamic-config-defaults - print JSON with dynamic config defaults

CheckedFind()

template<typename Container , typename Key >

auto utils::CheckedFind	(	Container &	container,
		const Key &	key
	)

Searches a map for an element and return a checked pointer to the found element.

Definition at line 86 of file algo.hpp.

ContainsIf()

template<typename Container , typename Pred >

bool utils::ContainsIf	(	const Container &	container,
		Pred	pred
	)

returns true if there is an element in container which satisfies the predicate

Definition at line 151 of file algo.hpp.

DaemonMain() [1/3]

int utils::DaemonMain	(	const boost::program_options::variables_map &	vm,
		const components::ComponentList &	components_list
	)

Calls components::Run with config file from –config parameter. Reports unhandled exceptions.

DaemonMain() [2/3]

int utils::DaemonMain	(	const components::InMemoryConfig &	config,
		const components::ComponentList &	components_list
	)

Calls components::Run with in-memory config. Reports unhandled exceptions.

DaemonMain() [3/3]

int utils::DaemonMain	(	int	argc,
		const char *const	argv[],
		const components::ComponentList &	components_list
	)

Parses command line arguments and calls components::Run with config file from –config parameter. See BaseRunOptions() for a list of options. Reports unhandled exceptions.

Examples

grpc-generic-proxy/main.cpp, postgresql/functional_tests/basic_chaos/postgres_service.cpp, samples/config_service/main.cpp, samples/flatbuf_service/main.cpp, samples/grpc_middleware_service/main.cpp, samples/grpc_service/main.cpp, samples/hello_service/main.cpp, samples/http_caching/main.cpp, samples/kafka_service/main.cpp, samples/mongo_service/main.cpp, samples/multipart_service/main.cpp, samples/postgres_auth/postgres_service.cpp, samples/postgres_service/main.cpp, samples/production_service/main.cpp, samples/redis_service/main.cpp, samples/s3api/main.cpp, samples/static_service/main.cpp, samples/tcp_full_duplex_service/main.cpp, samples/tcp_service/main.cpp, and samples/websocket_service/main.cpp.

enumerate()

template<typename Container >

constexpr auto utils::enumerate ( Container &&  iterable )

constexpr

Implementation of python-style enumerate function for range-for loops.

Parameters

iterable

Container to iterate

Returns

ContainerWrapper, which iterator after dereference returns pair of index and (!!!)non-const reference to element(it seems impossible to make this reference const). It can be used in "range based for loop" with "structured binding" like this

for (auto [pos, elem] : enumerate(someContainer)) {...}

Definition at line 85 of file enumerate.hpp.

Erase()

template<typename Container , typename T >

size_t utils::Erase	(	Container &	container,
		const T &	elem
	)

Erased elements and returns number of deleted elements.

Definition at line 136 of file algo.hpp.

EraseIf()

template<typename Container , typename Pred >

auto utils::EraseIf	(	Container &	container,
		Pred	pred
	)

Erased elements and returns number of deleted elements.

Definition at line 115 of file algo.hpp.

ExtractTimestampFromUuidV7()

std::chrono::system_clock::time_point utils::ExtractTimestampFromUuidV7

(

boost::uuids::uuid

uuid

)

Extracts timestamp from UUIDv7.

Returns point in time when uuid was generated.

Note

Due to implementation details time point may be inaccurate:

• implementation uses coarse clock, which have milliseconds precision (https://www.kernel.org/doc/html/latest/core-api/timekeeping.html)
• implementation may move timestamp forward in order to ensure monotonicity of generated uuids

FindOptional()

template<typename Container , typename Key >

auto utils::FindOptional	(	Container &	container,
		const Key &	key
	)

Returns std::nullopt if no key in associative container, otherwise returns std::optional with a copy of value.

Definition at line 78 of file algo.hpp.

FindOrDefault() [1/2]

template<typename Container , typename Key >

auto utils::FindOrDefault	(	Container &	container,
		const Key &	key
	)

Returns default value if no key in associative container, otherwise returns a copy of the stored value.

Definition at line 70 of file algo.hpp.

FindOrDefault() [2/2]

template<typename Container , typename Key , typename Default >

auto utils::FindOrDefault	(	Container &	container,
		const Key &	key,
		Default &&	def
	)

Returns default value if no key in associative container, otherwise returns a copy of the stored value.

Definition at line 62 of file algo.hpp.

FindOrNullptr()

template<typename Container , typename Key >

auto * utils::FindOrNullptr	(	Container &	container,
		const Key &	key
	)

Returns nullptr if no key in associative container, otherwise returns pointer to value.

Definition at line 50 of file algo.hpp.

ForEachIndex()

template<std::size_t Count, typename Func >

void utils::ForEachIndex

(

Func

func

)

Calls func with indices from range 0...<Count, wrapped in std::integral_constant.

Definition at line 33 of file constexpr_indices.hpp.

FromString()

template<typename T , typename StringType , typename = std::enable_if_t<std::is_convertible_v<StringType, std::string_view>>>

T utils::FromString

(

const StringType &

str

)

Extract the number contained in the string. No space characters or other extra characters allowed. Supported types:

• Integer types. Leading plus or minus is allowed. The number is always base-10.
• Floating-point types. The accepted number format is identical to std::strtod.

Template Parameters

T	The type of the number to be parsed

Parameters

str	The string that contains the number

Returns

The extracted number

Exceptions

std::runtime_error

if the string does not contain an integer or floating-point number in the specified format, or the string contains extra junk, or the number does not fit into the provided type

Examples

postgresql/functional_tests/basic_chaos/postgres_service.cpp.

Definition at line 171 of file from_string.hpp.

GenerateFixedArray()

template<class GeneratorFunc >

auto utils::GenerateFixedArray	(	std::size_t	size,
		GeneratorFunc &&	generator
	)

Applies generator to indices in the range [0, size), storing the results in a new utils::FixedArray. The generator is guaranteed to be invoked in the first-to-last order.

Parameters

size	How many objects to generate
generator	A functor that takes an index and returns an object for the FixedArray

Returns

FixedArray with the return objects of generator

Definition at line 164 of file fixed_array.hpp.

GetCurrentThreadName()

std::string utils::GetCurrentThreadName

(

)

Get the name of the current thread.

Thread names should only be used for debugging purposes. Thread names aren't required to be preserved exactly due to the system limit on thread name length.

Returns

the current thread name

Exceptions

std::system_error

on error

GetIf() [1/2]

template<typename Leaf >

constexpr auto * utils::GetIf ( Leaf &&  leaf )

constexpr

Definition at line 28 of file get_if.hpp.

GetIf() [2/2]

template<typename Root , typename Head , typename... Tail>

constexpr auto * utils::GetIf ( Root &&  root, Head &&  head, Tail &&...  tail  )

constexpr

Dereferences a chain of indirections and compositions, returns nullptr if one of the chain elements is not set.

    struct C {};
    struct B {
        std::unique_ptr<C> c = std::make_unique<C>();
    };
    struct A {
        std::shared_ptr<B> b = std::make_shared<B>();
    };
 
    auto a = std::make_optional<A>();
    EXPECT_EQ(utils::GetIf(a, &A::b, &B::c), a->b->c.get());
    EXPECT_EQ(utils::GetIf(a, &A::b), a->b.get());
    EXPECT_EQ(utils::GetIf(a), &*a);
    a->b->c.reset();
    EXPECT_EQ(utils::GetIf(a, &A::b, &B::c), static_cast<C*>(nullptr));
    EXPECT_EQ(utils::GetIf(a, &A::b), a->b.get());
    EXPECT_EQ(utils::GetIf(a), &*a);
    a->b.reset();
    EXPECT_EQ(utils::GetIf(a, &A::b, &B::c), static_cast<C*>(nullptr));
    EXPECT_EQ(utils::GetIf(a, &A::b), static_cast<B*>(nullptr));
    EXPECT_EQ(utils::GetIf(a), &*a);
    a.reset();
    EXPECT_EQ(utils::GetIf(a, &A::b, &B::c), static_cast<C*>(nullptr));
    EXPECT_EQ(utils::GetIf(a, &A::b), static_cast<B*>(nullptr));
    EXPECT_EQ(utils::GetIf(a), static_cast<A*>(nullptr));

Definition at line 41 of file get_if.hpp.

GetNearestString()

template<typename StringViews , typename DistanceFunc = std::size_t (*)(std::string_view, std::string_view)>

std::optional< std::string_view > utils::GetNearestString	(	const StringViews &	strings,
		std::string_view	key,
		std::size_t	max_distance,
		DistanceFunc	distance_func = &utils::GetLevenshteinDistance
	)

Returns a nearest string for a key from a bunch of strings.

Definition at line 29 of file distances.hpp.

GetUserverIdentifier()

const char * utils::GetUserverIdentifier ( )

noexcept

Returns

zero-terminated string with description of the server as "userver/{GetUserverVersion()} ({__DATE__}; rv: {GetUserverHash()})"

GetUserverVcsRevision()

const char * utils::GetUserverVcsRevision ( )

noexcept

Returns

zero-terminated string with GIT short hash of userver repo

GetUserverVersion()

const char * utils::GetUserverVersion ( )

noexcept

Returns

zero-terminated string with version as "major.minor.patch"

hash_value()

template<class Tag , class T , StrongTypedefOps Ops>

std::size_t utils::hash_value

(

const StrongTypedef< Tag, T, Ops > &

v

)

Definition at line 411 of file strong_typedef.hpp.

IsMainThread()

bool utils::IsMainThread ( )

noexcept

Returns

true if this is the thread in which main() was started

IsStrongTypedefLoggable()

constexpr bool utils::IsStrongTypedefLoggable ( StrongTypedefOps  Ops )

constexpr

Definition at line 343 of file strong_typedef.hpp.

LogErrorAndThrow()

template<typename T = std::runtime_error>

void utils::LogErrorAndThrow

(

const std::string &

error_message

)

Logs error_message and throws an exception ith that message.

Definition at line 17 of file exception.hpp.

make_intrusive_ptr()

template<class Target , class... Args>

boost::intrusive_ptr< Target > utils::make_intrusive_ptr

(

Args &&...

args

)

Factory function for boost::intrusive_ptr, like std::make_unique.

Definition at line 17 of file make_intrusive_ptr.hpp.

MakeCheckedPtr()

template<typename T >

constexpr CheckedPtr< T > utils::MakeCheckedPtr ( T *  ptr )

constexprnoexcept

Definition at line 73 of file checked_pointer.hpp.

MakeLazyCachePtr()

template<typename Cache >

LazySharedPtr< typename Cache::DataType > utils::MakeLazyCachePtr

(

Cache &

cache

)

Make a lazy pointer to the data of a cache.

The cache type must have:

• DataType member type;
• Get() -> utils::SharedReadablePtr<DataType> method.

For example, components::CachingComponentBase satisfies these requirements.

Definition at line 146 of file lazy_shared_ptr.hpp.

MakeSharedReadable()

template<typename T , typename... Args>

SharedReadablePtr< T > utils::MakeSharedReadable

(

Args &&...

args

)

Definition at line 146 of file shared_readable_ptr.hpp.

MakeSharedRef()

template<typename U , typename... Args>

SharedRef< U > utils::MakeSharedRef

(

Args &&...

args

)

An equivalent of std::make_shared for SharedRef.

Definition at line 110 of file not_null.hpp.

MakeTrivialBiMap()

template<const auto & Keys, const auto & Values>

constexpr auto utils::MakeTrivialBiMap ( )

constexpr

Zips two global constexpr arrays into an utils::TrivialBiMap.

Definition at line 988 of file trivial_map.hpp.

MakeTrivialSet()

template<const auto & Values>

constexpr auto utils::MakeTrivialSet ( )

constexpr

Definition at line 995 of file trivial_map.hpp.

MakeUniqueRef()

template<typename U , typename... Args>

UniqueRef< U > utils::MakeUniqueRef

(

Args &&...

args

)

An equivalent of std::make_unique for UniqueRef.

Definition at line 116 of file not_null.hpp.

numeric_cast()

template<typename To , typename From >

constexpr To utils::numeric_cast ( From  input )

constexpr

Detects loss of range when a numeric type is converted, and throws an exception if the range cannot be preserved

Example usage:

    EXPECT_EQ(utils::numeric_cast<std::uint16_t>(0xffff), 0xffffu);
    EXPECT_THROW(utils::numeric_cast<std::uint16_t>(0x10000), std::runtime_error);
 
    EXPECT_EQ(utils::numeric_cast<std::uint16_t>(0), 0);
    EXPECT_THROW(utils::numeric_cast<std::uint16_t>(-1), std::runtime_error);

Definition at line 31 of file numeric_cast.hpp.

operator!=() [1/8]

constexpr bool utils::operator!= ( BytesPerSecond  lhs, BytesPerSecond  rhs  )

constexpr

Definition at line 24 of file bytes_per_second.hpp.

operator!=() [2/8]

template<class T >

constexpr bool utils::operator!= ( const CachedHash< T > &  x, const CachedHash< T > &  y  )

constexpr

Compares utils::CachedHash by hash first and then by keys.

Definition at line 30 of file cached_hash.hpp.

operator!=() [3/8]

template<typename T >

bool utils::operator!=	(	const SharedReadablePtr< T > &	ptr,
		std::nullptr_t
	)

Definition at line 136 of file shared_readable_ptr.hpp.

operator!=() [4/8]

template<std::size_t N>

bool utils::operator!=	(	const SmallString< N > &	str1,
		const SmallString< N > &	str2
	)

Definition at line 189 of file small_string.hpp.

operator!=() [5/8]

template<typename Enum >

bool utils::operator!=	(	Enum	lhs,
		const AtomicFlags< Enum > &	rhs
	)

Definition at line 372 of file flags.hpp.

operator!=() [6/8]

template<typename Enum >

constexpr bool utils::operator!= ( Enum  lhs, Flags< Enum >  rhs  )

constexpr

Definition at line 214 of file flags.hpp.

operator!=() [7/8]

template<class T , class U >

constexpr bool utils::operator!= ( OptionalRef< T >  lhs, OptionalRef< U >  rhs  )

constexprnoexcept

Definition at line 111 of file optional_ref.hpp.

operator!=() [8/8]

template<typename T >

bool utils::operator!=	(	std::nullptr_t	,
		const SharedReadablePtr< T > &	ptr
	)

Definition at line 141 of file shared_readable_ptr.hpp.

operator&() [1/3]

template<typename Enum >

Flags< Enum > utils::operator&	(	Enum	lhs,
		const AtomicFlags< Enum > &	rhs
	)

Definition at line 362 of file flags.hpp.

operator&() [2/3]

template<typename Enum >

constexpr Flags< Enum > utils::operator& ( Enum  lhs, Flags< Enum >  rhs  )

constexpr

Definition at line 204 of file flags.hpp.

operator&() [3/3]

constexpr bool utils::operator& ( StrongTypedefOps  op, StrongTypedefOps  mask  )

constexprnoexcept

Definition at line 48 of file strong_typedef.hpp.

operator<<() [1/3]

template<typename T >

logging::LogHelper & utils::operator<<	(	logging::LogHelper &	lh,
		const Box< T > &	box
	)

Definition at line 192 of file box.hpp.

operator<<() [2/3]

template<class Tag , class T , StrongTypedefOps Ops>

logging::LogHelper & utils::operator<<	(	logging::LogHelper &	os,
		const StrongTypedef< Tag, T, Ops > &	v
	)

Definition at line 327 of file strong_typedef.hpp.

operator<<() [3/3]

template<class Tag , class T , StrongTypedefOps Ops>

std::ostream & utils::operator<<	(	std::ostream &	os,
		const StrongTypedef< Tag, T, Ops > &	v
	)

Ostreams and Logging.

Definition at line 321 of file strong_typedef.hpp.

operator==() [1/10]

constexpr bool utils::operator== ( BytesPerSecond  lhs, BytesPerSecond  rhs  )

constexpr

Definition at line 22 of file bytes_per_second.hpp.

operator==() [2/10]

template<class T >

constexpr bool utils::operator== ( const CachedHash< T > &  x, const CachedHash< T > &  y  )

constexpr

Compares utils::CachedHash by hash first and then by keys.

Definition at line 24 of file cached_hash.hpp.

operator==() [3/10]

template<typename T >

bool utils::operator==	(	const SharedReadablePtr< T > &	ptr,
		std::nullptr_t
	)

Definition at line 126 of file shared_readable_ptr.hpp.

operator==() [4/10]

template<std::size_t N>

bool utils::operator==	(	const SmallString< N > &	str,
		std::string_view	sv
	)

Definition at line 174 of file small_string.hpp.

operator==() [5/10]

template<std::size_t N>

bool utils::operator==	(	const SmallString< N > &	str1,
		const SmallString< N > &	str2
	)

Definition at line 184 of file small_string.hpp.

operator==() [6/10]

template<typename Enum >

bool utils::operator==	(	Enum	lhs,
		const AtomicFlags< Enum > &	rhs
	)

Definition at line 367 of file flags.hpp.

operator==() [7/10]

template<typename Enum >

constexpr bool utils::operator== ( Enum  lhs, Flags< Enum >  rhs  )

constexpr

Definition at line 209 of file flags.hpp.

operator==() [8/10]

template<class T , class U >

constexpr bool utils::operator== ( OptionalRef< T >  lhs, OptionalRef< U >  rhs  )

constexprnoexcept

Definition at line 105 of file optional_ref.hpp.

operator==() [9/10]

template<typename T >

bool utils::operator==	(	std::nullptr_t	,
		const SharedReadablePtr< T > &	ptr
	)

Definition at line 131 of file shared_readable_ptr.hpp.

operator==() [10/10]

template<std::size_t N>

bool utils::operator==	(	std::string_view	sv,
		const SmallString< N > &	str
	)

Definition at line 179 of file small_string.hpp.

operator|() [1/3]

template<typename Enum >

Flags< Enum > utils::operator|	(	Enum	lhs,
		const AtomicFlags< Enum > &	rhs
	)

Definition at line 357 of file flags.hpp.

operator|() [2/3]

template<typename Enum >

constexpr Flags< Enum > utils::operator| ( Enum  lhs, Flags< Enum >  rhs  )

constexpr

Definition at line 199 of file flags.hpp.

operator|() [3/3]

constexpr auto utils::operator| ( StrongTypedefOps  op1, StrongTypedefOps  op2  )

constexprnoexcept

Definition at line 52 of file strong_typedef.hpp.

OptionalTransform()

template<typename T , typename Func >

auto utils::OptionalTransform	(	T &&	opt,
		Func	func
	)		-> std::optional<decltype(std::move(func)(*std::forward<T>(opt)))>

A polyfill for C++23 monadic operations for std::optional.

Definition at line 26 of file optionals.hpp.

Parse() [1/5]

template<typename T , typename Value >

std::enable_if_t< formats::common::kIsFormatValue< Value > &&IsStrongTypedef< T >{}, T > utils::Parse	(	const Value &	source,
		formats::parse::To< T >
	)

Definition at line 349 of file strong_typedef.hpp.

Parse() [2/5]

template<class Value >

BytesPerSecond utils::Parse	(	const Value &	v,
		formats::parse::To< BytesPerSecond >
	)

Definition at line 31 of file bytes_per_second.hpp.

Parse() [3/5]

template<typename Value , typename T >

Box< T > utils::Parse	(	const Value &	value,
		formats::parse::To< Box< T > >
	)

Definition at line 177 of file box.hpp.

Parse() [4/5]

template<typename Value , typename T >

std::enable_if_t< formats::common::kIsFormatValue< Value >, DefaultDict< T > > utils::Parse	(	const Value &	value,
		formats::parse::To< DefaultDict< T > >
	)

Definition at line 158 of file default_dict.hpp.

Parse() [5/5]

template<typename Value , std::size_t N>

SmallString< N > utils::Parse	(	const Value &	value,
		formats::parse::To< SmallString< N > >
	)

Definition at line 21 of file small_string_serialization.hpp.

ParseFromValueString()

template<typename ExceptionType = void, typename Value , typename BuilderFunc >

auto utils::ParseFromValueString	(	const Value &	value,
		TrivialBiMap< BuilderFunc >	map
	)

Parses and returns whatever is specified by map from a formats::json::Value or another format's Value.

Exceptions

ExceptionType

or Value::Exception by default, if value is not a string, or if value is not contained in map.

See also

Formats (JSON, YAML, BSON, ...)

Definition at line 909 of file trivial_map.hpp.

PrintTo()

template<class Tag , class T , StrongTypedefOps Ops>

void utils::PrintTo	(	const StrongTypedef< Tag, T, Ops > &	v,
		std::ostream *	os
	)

gtest formatter for utils::StrongTypedef

Definition at line 417 of file strong_typedef.hpp.

ProjectedFind()

template<typename Container , typename Key >

auto utils::ProjectedFind	(	Container &	set,
		const Key &	key
	)

An equivalent of std::unordered_map::find for utils::ProjectedUnorderedSet and utils::ProjectedSet.

Only required for pre-C++20 compilers, can just use set.find(key) otherwise.

Note

Always returns const iterator, even for a non-const set parameter.

Definition at line 122 of file projected_set.hpp.

ProjectedInsertOrAssign()

template<typename Container , typename Value >

void utils::ProjectedInsertOrAssign	(	Container &	set,
		Value &&	value
	)

An equivalent of std::unordered_map::insert_or_assign for utils::ProjectedUnorderedSet and utils::ProjectedSet.

Definition at line 111 of file projected_set.hpp.

Rand()

std::uint32_t utils::Rand

(

)

Generate a random number in the whole uint32_t range.

Note

The used random generator is not cryptographically secure

Warning

Don't use Rand() % N, use RandRange instead

Examples

core/src/engine/mutex_benchmark.cpp.

RandRange() [1/2]

template<typename T >

T utils::RandRange	(	T	from_inclusive,
		T	to_exclusive
	)

Generates a random number in range [from, to)

Note

The used random generator is not cryptographically secure

from_inclusive must be less than to_exclusive

Definition at line 86 of file rand.hpp.

RandRange() [2/2]

template<typename T >

T utils::RandRange

(

T

to_exclusive

)

Generates a random number in range [0, to)

Note

The used random generator is not cryptographically secure

Definition at line 101 of file rand.hpp.

regex_match()

bool utils::regex_match	(	std::string_view	str,
		match_results &	m,
		const regex &	pattern
	)

Returns true if the specified regular expression matches the whole of the input. Fills in what matched in m.

Note

m may be clobbered on failure.

regex_replace() [1/2]

std::string utils::regex_replace	(	std::string_view	str,
		const regex &	pattern,
		Re2Replacement	repl
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

See also

utils::Re2Replacement

regex_replace() [2/2]

std::string utils::regex_replace	(	std::string_view	str,
		const regex &	pattern,
		std::string_view	repl
	)

Create a new string where all regular expression matches replaced with repl.

Interprets repl as a literal, does not support substitutions.

See also

utils::Re2Replacement

regex_search()

bool utils::regex_search	(	std::string_view	str,
		match_results &	m,
		const regex &	pattern
	)

Determines whether the regular expression matches anywhere in the target character sequence. Fills in what matched in m.

Note

m may be clobbered on failure.

Serialize() [1/5]

template<typename Value , typename T >

Value utils::Serialize	(	const Box< T > &	value,
		formats::serialize::To< Value >
	)

Definition at line 182 of file box.hpp.

Serialize() [2/5]

template<typename Value , std::size_t N>

Value utils::Serialize	(	const SmallString< N > &	value,
		formats::serialize::To< Value >
	)

Definition at line 16 of file small_string_serialization.hpp.

Serialize() [3/5]

template<typename T , typename Value >

std::enable_if_t< IsStrongTypedef< T >{}, Value > utils::Serialize	(	const T &	object,
		formats::serialize::To< Value >
	)

Definition at line 354 of file strong_typedef.hpp.

Serialize() [4/5]

template<class Value >

Value utils::Serialize	(	StringLiteral	literal,
		formats::serialize::To< Value >
	)

Definition at line 54 of file string_literal.hpp.

Serialize() [5/5]

template<class Value >

Value utils::Serialize	(	zstring_view	view,
		formats::serialize::To< Value >
	)

Definition at line 53 of file zstring_view.hpp.

SetCurrentThreadIdleScheduling()

void utils::SetCurrentThreadIdleScheduling

(

)

Set priority of the OS thread to IDLE (the lowest one)

Exceptions

std::system_error

SetCurrentThreadLowPriorityScheduling()

void utils::SetCurrentThreadLowPriorityScheduling

(

)

Set priority of the OS thread to low (but not the lowest one)

Exceptions

std::system_error

SetCurrentThreadName()

void utils::SetCurrentThreadName

(

std::string_view

name

)

Set the name of the current thread.

This function should only be used from drivers that create their own threads! Users should normally rely on the coroutine engine instead of creating additional threads.

There is a system limit on thread name length, e.g. 15 chars on Linux. The name is automatically cut to fit the limit.

Parameters

name	the new thread name

Exceptions

std::system_error

on error

Shuffle()

template<typename Container >

void utils::Shuffle

(

Container &

container

)

Shuffles the elements within the container.

Note

The method used for determining a random permutation is not cryptographically secure

Definition at line 109 of file rand.hpp.

StrCat()

template<typename ResultString = std::string, typename... Strings>

ResultString utils::StrCat

(

const Strings &...

strings

)

Concatenates multiple std::string_view-convertible items.

Definition at line 24 of file algo.hpp.

StringToBytesPerSecond()

BytesPerSecond utils::StringToBytesPerSecond

(

const std::string &

data

)

Understands all the date-rate unit suffixes from https://en.wikipedia.org/wiki/Data-rate_units#Conversion_table

StringToDuration()

std::chrono::milliseconds utils::StringToDuration

(

std::string_view

data

)

Converts strings like "10s", "5d", "1h" to durations.

Understands the following suffixes: s - seconds ms - milliseconds m - minutes h - hours d - days

StrongCast() [1/2]

template<typename Target , typename Tag , typename T , StrongTypedefOps Ops, typename Enable >

constexpr Target utils::StrongCast ( const StrongTypedef< Tag, T, Ops, Enable > &  src )

constexpr

Explicitly cast from one strong typedef to another, to replace constructions SomeStrongTydef{utils::UnderlyingValue(another_strong_val)} with utils::StrongCast<SomeStrongTydef>(another_strong_val)

Definition at line 389 of file strong_typedef.hpp.

StrongCast() [2/2]

template<typename Target , typename Tag , typename T , StrongTypedefOps Ops, typename Enable >

constexpr Target utils::StrongCast ( StrongTypedef< Tag, T, Ops, Enable > &&  src )

constexpr

Definition at line 400 of file strong_typedef.hpp.

SuggestNearestName()

template<typename StringViews >

std::string utils::SuggestNearestName	(	const StringViews &	strings,
		std::string_view	key
	)

Returns a suggestion for a key.

Definition at line 58 of file distances.hpp.

ToLongLong()

constexpr long long utils::ToLongLong ( BytesPerSecond  x )

constexpr

Definition at line 20 of file bytes_per_second.hpp.

ToString() [1/3]

template<class T >

std::string utils::ToString

(

const std::optional< T > &

from

)

Converts std::optional to a string, empty value represented as "--".

Definition at line 20 of file optionals.hpp.

ToString() [2/3]

template<typename Tag , StrongTypedefOps Ops>

std::string utils::ToString

(

const StrongTypedef< Tag, std::string, Ops > &

object

)

Definition at line 366 of file strong_typedef.hpp.

ToString() [3/3]

template<typename Tag , typename T , StrongTypedefOps Ops, std::enable_if_t< meta::kIsInteger< T >, bool > = true>

std::string utils::ToString

(

const StrongTypedef< Tag, T, Ops > &

object

)

Definition at line 372 of file strong_typedef.hpp.

UnderlyingValue() [1/3]

template<class Tag , class T , StrongTypedefOps Ops>

constexpr decltype(auto) utils::UnderlyingValue ( const StrongTypedef< Tag, T, Ops > &  v )

constexprnoexcept

Definition at line 334 of file strong_typedef.hpp.

UnderlyingValue() [2/3]

template<class Tag , class T , StrongTypedefOps Ops>

constexpr T utils::UnderlyingValue ( StrongTypedef< Tag, T, Ops > &&  v )

constexprnoexcept

Definition at line 339 of file strong_typedef.hpp.

UnderlyingValue() [3/3]

template<class T , std::enable_if_t< std::is_enum_v< T >, int > = 0>

constexpr auto utils::UnderlyingValue ( T  v )

constexprnoexcept

Function that extracts integral value from enum or StrongTypedef.

Definition at line 15 of file underlying_value.hpp.

Visit() [1/3]

template<class... Args, class... Ts>

constexpr decltype(auto) utils::Visit ( const std::variant< Args... > &  var, Ts &&...  ts  )

constexpr

Definition at line 24 of file overloaded.hpp.

Visit() [2/3]

template<class... Args, class... Ts>

constexpr decltype(auto) utils::Visit ( std::variant< Args... > &&  var, Ts &&...  ts  )

constexpr

Definition at line 34 of file overloaded.hpp.

Visit() [3/3]

template<class... Args, class... Ts>

constexpr decltype(auto) utils::Visit ( std::variant< Args... > &  var, Ts &&...  ts  )

constexpr

Definition at line 29 of file overloaded.hpp.

WithConstexprIndex()

template<std::size_t Count, typename Func >

void utils::WithConstexprIndex	(	std::size_t	runtime_index,
		Func	func
	)

Calls func with runtime_index wrapped in std::integral_constant.

Definition at line 39 of file constexpr_indices.hpp.

WithDefaultRandom()

template<typename Func >

decltype(auto) utils::WithDefaultRandom

(

Func &&

func

)

Calls func with a thread-local UniformRandomBitGenerator (specifically of type utils::RandomBase).

Note

The provided RandomBase instance is not cryptographically secure.

func should not contain any task context switches. That is, it should not use any userver synchronization primitives and should not access userver-based web or database clients.

func should not store the reference to the provided thread-local variable for use outside of the WithThreadLocal scope.

Prefer utils::RandRange if possible.

Usage example

Standard distributions can be passed to WithDefaultRandom directly:

        std::uniform_int_distribution<std::uint64_t> distribution{1, 6};
        const auto x = utils::WithDefaultRandom(distribution);

A lambda can be passed to perform a series of operations more efficiently:

    std::vector<std::uint64_t> random_numbers;
    random_numbers.reserve(kIterations);
 
    // utils::WithDefaultRandom induces some overhead to ensure coroutine-safety.
    // In a performance-critical code section, a single WithDefaultRandom call is
    // more efficient than multiple `WithDefaultRandom(distribution)`.
    utils::WithDefaultRandom([&](utils::RandomBase& rng) {
        std::uniform_int_distribution<std::uint64_t> distribution{1, 6};
        for (int iter = 0; iter < kIterations; ++iter) {
            random_numbers.push_back(distribution(rng));
        }
    });

Parameters

func	functor that will be invoked with the RNG

Returns

The invocation result of func

Definition at line 77 of file rand.hpp.

WithSafeHash() [1/8]

template<typename Key , typename Value >

auto utils::WithSafeHash

(

const std::unordered_map< Key, Value > &

map

)

Converts an unordered [multi-]map or set with the default hash to a map with utils::StrCaseHash. This might be useful when converting guaranteed-to-be-safe data to a common operating format.

Definition at line 22 of file str_icase_containers.hpp.

WithSafeHash() [2/8]

template<typename Key , typename Value >

auto utils::WithSafeHash

(

const std::unordered_multimap< Key, Value > &

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 34 of file str_icase_containers.hpp.

WithSafeHash() [3/8]

template<typename Key >

auto utils::WithSafeHash

(

const std::unordered_multiset< Key > &

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 58 of file str_icase_containers.hpp.

WithSafeHash() [4/8]

template<typename Key >

auto utils::WithSafeHash

(

const std::unordered_set< Key > &

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 46 of file str_icase_containers.hpp.

WithSafeHash() [5/8]

template<typename Key , typename Value >

auto utils::WithSafeHash

(

std::unordered_map< Key, Value > &&

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 28 of file str_icase_containers.hpp.

WithSafeHash() [6/8]

template<typename Key , typename Value >

auto utils::WithSafeHash

(

std::unordered_multimap< Key, Value > &&

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 40 of file str_icase_containers.hpp.

WithSafeHash() [7/8]

template<typename Key >

auto utils::WithSafeHash

(

std::unordered_multiset< Key > &&

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 64 of file str_icase_containers.hpp.

WithSafeHash() [8/8]

template<typename Key >

auto utils::WithSafeHash

(

std::unordered_set< Key > &&

map

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 52 of file str_icase_containers.hpp.

WriteToStream() [1/2]

template<typename StringBuilder , typename T >

void utils::WriteToStream	(	const Box< T > &	value,
		StringBuilder &	sw
	)

Definition at line 187 of file box.hpp.

WriteToStream() [2/2]

template<typename T , typename StringBuilder >

std::enable_if_t< IsStrongTypedef< T >{}> utils::WriteToStream	(	const T &	object,
		StringBuilder &	sw
	)

Definition at line 360 of file strong_typedef.hpp.

Variable Documentation

kDefaultDictDefaultName

constexpr std::string_view utils::kDefaultDictDefaultName = "__default__"

inlineconstexpr

Name of the key with default value for utils::DefaultDict.

Definition at line 19 of file default_dict.hpp.

kStrictMatch

constexpr bool utils::kStrictMatch = true

inlineconstexpr

Helper constant to use with FastPimpl.

Definition at line 17 of file fast_pimpl.hpp.