util

Namespaces

```
namespace compat
```

Records

Functions

lib::statusor::StatusOr<std::string> ReadTextFile (const Path & file_path)

lib::statusor::StatusOr<std::string> ReadNonEmptyTextFile (const Path & file_path)

lib::statusor::StatusOr<std::string> ReadHexFile (const Path & file_path)

std::string ReadHexFileOrDefault (const Path & file_path, const std::string & default_string)

std::string ReadHexFileOrDefault (const std::string & file_path, const std::string & default_string)

DEPRECATED: TODO(https://fxbug.dev/278930401): Remove once not used in Fuchsia

template <typename U, class... Args>

NotNullUniquePtr<U> MakeNotNullUniquePtr (Args &&... args)

template <typename U, typename V, class... Args>

NotNullUniquePtr<V> WrapNotNullUniquePtrOrDefault (std::unique_ptr<V> && other, Args &&... args)

template <typename U>

NotNullUniquePtr<U> TESTONLY_TakeRawPointer (U * other)

template <typename U>

lib::statusor::StatusOr<NotNullUniquePtr<U>> WrapNotNullUniquePtr (std::unique_ptr<U> && other)

lib::statusor::StatusOr<uint32_t> TimePointToHourId (std::chrono::system_clock::time_point time_point, const util::CivilTimeConverterInterface & civil_time_converter, const MetricDefinition & metric)

Returns the hour ID for a time point, with respect to the time zone specified by `metric`'s time

zone policy. Prefer `TimeInfo::FromTimePoint()` when both the day index and hour ID are needed.

lib::statusor::StatusOr<uint32_t> TimePointToDayIndex (std::chrono::system_clock::time_point time_point, const util::CivilTimeConverterInterface & civil_time_converter, const MetricDefinition & metric)

Returns the day index for a time point, with respect to the time zone specified by `metric`'s

time zone policy. Prefer `TimeInfo::FromTimePoint()` when both the day index and hour ID are

needed.

```
uint32_t TimePointToHourIdUtc (std::chrono::system_clock::time_point time_point)
```
Returns the hour id for a time point, with respect to UTC. Prefer

`TimeInfo::FromTimePointUtc()` when both the day index and hour ID are needed.
```
uint32_t TimePointToDayIndexUtc (std::chrono::system_clock::time_point time_point)
```
Returns the day index for a time point, with respect to UTC. Prefer

`TimeInfo::FromTimePointUtc()` when both the day index and hour ID are needed.
```
uint32_t TimeToHourId (time_t time, MetricDefinition::TimeZonePolicy time_zone)
```
DEPRECATED: to be replaced by `TimePointToHourId`.

Returns the hour identifier. The hour identifier is calculated as follows:

(TimeToDayIndex(time, time_zone) * 48) + (tm_hour * 2) + (tm_dst ? 0 : 1)

See: https://fuchsia.googlesource.com/cobalt/+/master/docs/hour_id.md
```
uint32_t TimeToDayIndex (time_t time, MetricDefinition::TimeZonePolicy time_zone)
```
DEPRECATED: to be replaced by `TimePointToDayIndex`.

Returns the day index corresponding to |time| in the given |time_zone|

or UINT32_MAX if |time_zone| is not valid. |time| must be a Unix timestamp,

that is a number of Unix seconds since the Unix epoch.
```
time_t MidnightUtcFromDayIndex (uint32_t day_index)
```
Returns the Unix time for midnight of the day with the given |day_index|

in UTC.
```
uint32_t CalendarDateToDayIndex (const CalendarDate & calendar_date)
```
Converts the given CalendarDate to a Cobalt Day Index. If the fields of

calendar_date do not make sense as a real day of the calendar

(for example if month=13) then the result is undefined. If the

specified date is prior to January 1, 1970 or not before the year 10,000

then the result is undefined.
```
CalendarDate DayIndexToCalendarDate (uint32_t day_index)
```
Converts the given day_index to a CalendarDate, necessarily on or

after January 1, 1970.
```
uint32_t DayIndexToWeekIndex (uint32_t day_index)
```
Given a day_index returns the index of the Cobalt week epoch

containing that date.
```
uint32_t DayIndexToHourIdNoDst (uint32_t day_index)
```
Given a day index, returns the hour identifier for the start of that day, assuming that DST is

not in force.
```
uint32_t HourIdToDayIndex (uint32_t hour_id)
```
Given an hour identifier, returns the index of the Cobalt day containing that hour.
```
uint32_t CalendarDateToWeekIndex (const CalendarDate & calendar_date)
```
Given a CalendarDate returns the index of the Cobalt week epoch

containing that date. If the fields of calendar_date do not make sense as a

real day of the calendar (for example if month=13) then the result is

undefined. If the specified date is prior to January 1, 1970 then the result

is undefined.
```
CalendarDate WeekIndexToCalendarDate (uint32_t week_index)
```
Given the index of a Cobalt week epoch returns the CalendarDate for the first

day of that week epoch. In all cases except week_index=0 the

returned date will be a Sunday. If week_index=0 the returned date will

be day zero: Thu 1970-1-1.
```
uint32_t DayIndexToMonthIndex (uint32_t day_index)
```
Given a day_index returns the index of the Cobalt month epoch

containing that date.
```
uint32_t CalendarDateToMonthIndex (const CalendarDate & calendar_date)
```
Given a CalendarDate returns the index of the Cobalt month epoch

containing that date. If the fields of

calendar_date do not make sense as a real day of the calendar (for example if

month=13) then the result is undefined. If the specified date is prior to

January 1, 1970 then the result is undefined.
```
CalendarDate MonthIndexToCalendarDate (uint32_t month_index)
```
Given the index of a Cobalt month epoch returns the CalendarDate for the

first day of that month epoch.
```
int64_t ToUnixSeconds (std::chrono::system_clock::time_point t)
```
Returns the the given time as a number of seconds since the Unix epoch.

int64_t DayIndexToUnixSeconds (uint32_t day_index)

int64_t HourIdToUnixSeconds (uint32_t hour_id)

```
std::chrono::system_clock::time_point FromUnixSeconds (int64_t seconds)
```
Returns the given number of seconds since the Unix epoch as a time_point.
```
template <typename T, typename U, class... Args>
```
```
NotNullUniquePtr<U> WrapNotNullUniquePtrOrDefault (std::unique_ptr<U> && other, Args &&... args)
```
WrapNotNullUniquePtrOrDefault allows converting std::unique_ptr into a NotNullUniquePtr. It

does this by taking arguments for a fallback constructor after the std::unique_ptr argument. If

the provided std::unique_ptr happens to be null, the fallback constructor will be used. This

way the pointer is guaranteed never to be null.

Defined at line 98 of file ../../third_party/cobalt/src/lib/util/not_null.h

std::ostream & operator<< (std::ostream & o, const TimeInfo & a)

Stream operator useful for logging TimeInfo objects.

std::ostream & operator<< (std::ostream & os, const NamedType<T, Tag> & other)

Defined at line 83 of file ../../third_party/cobalt/src/lib/util/named_type.h

```
template <typename T, class... Args>
```
```
NotNullUniquePtr<T> MakeNotNullUniquePtr (Args &&... args)
```
MakeNotNullUniquePtr is equivalent to std::make_unique, and constructs a NotNullUniquePtr that

is guaranteed to not be null.

Defined at line 89 of file ../../third_party/cobalt/src/lib/util/not_null.h

template <typename T>

lib::statusor::StatusOr<NotNullSharedPtr<T>> MaybeWrapNotNullSharedPtr (std::shared_ptr<T> && other)

Defined at line 252 of file ../../third_party/cobalt/src/lib/util/not_null.h

template <typename U>

lib::statusor::StatusOr<NotNullSharedPtr<U>> MaybeWrapNotNullSharedPtr (std::shared_ptr<U> && other)

```
template <typename T>
```
```
NotNullUniquePtr<T> TESTONLY_TakeRawPointer (T * other)
```
TESTONLY_TakeRawPointer takes a (possible null) pointer to an object of type T. If the pointer

is non-null, it will return a NotNullUniquePtr

<T

> that takes ownership of the provided pointer.

Otherwise it will CHECK-fail.

Defined at line 110 of file ../../third_party/cobalt/src/lib/util/not_null.h
```
template <typename T>
```
```
lib::statusor::StatusOr<NotNullUniquePtr<T>> WrapNotNullUniquePtr (std::unique_ptr<T> && other)
```
WrapNotNullUniquePtr takes a (possible null) pointer to an object of type T. If the pointer is

non-null, it will return a NotNullUniquePtr

<T

> that takes ownership of the provided pointer.

Otherwise it will return a non-OK status.

Defined at line 119 of file ../../third_party/cobalt/src/lib/util/not_null.h