class Status

Create a status from a `base_status` and a `loc`. The `loc` will be

appended to the location chain of the new status, iff the `base_status` is

not ok and has non-empty msg.

Appends the `loc` to the current location chain inside the status, iff the

status is non-ok and contains a non-empty message.

Status::WithSourceLocation()

Returns a copy of the current status, with `loc` appended to its location

chain iff the status is non-ok and contains a non-empty message.

Example:

if (Status status = Foo(); !status.ok()) {

return status.WithSourceLocation();

}

Status::WithSourceLocation()

Appends the `loc` to the current location chain inside the status iff the

status is non-ok and contains a non-empty message, and returns an rvalue

reference to `*this`.

Example:

Status Finalize(...);

Status DoSomething(...) {

...

return Finalize().WithSourceLocation();

}

This default constructor creates an OK status with no message or payload.

Avoid this constructor and prefer explicit construction of an OK status

with `absl::OkStatus()`.

Creates a status in the canonical error space with the specified

`absl::StatusCode` and error message. If `code == absl::StatusCode::kOk`,

`msg` is ignored and an object identical to an OK status is constructed.

The `msg` string must be in UTF-8. The implementation may complain (e.g.,

by printing a warning) if it is not.

The `loc` is the SourceLocation of the callsite. It will be stored in the

Status iff `code != absl::StatusCode::kOk` and `!msg.empty()`.

Same as above but for rvalue string.

Note: using a template to disambiguate the case of matching string_view and

string

&

&

(e.g. char*) as a template lowers the priority of the overload.

The moved-from state is valid but unspecified.

Status::Update()

Updates the existing status with `new_status` provided that `this->ok()`.

If the existing status already contains a non-OK error, this update has no

effect and preserves the current data. Note that this behavior may change

in the future to augment a current non-ok status with additional

information about `new_status`.

`Update()` provides a convenient way of keeping track of the first error

encountered.

Example:

// Instead of "if (overall_status.ok()) overall_status = new_status"

overall_status.Update(new_status);

Status::ok()

Returns `true` if `this->code()` == `absl::StatusCode::kOk`,

indicating the absence of an error.

Prefer checking for an OK status using this member function.

Status::code()

Returns the canonical error code of type `absl::StatusCode` of this status.

Status::raw_code()

Returns a raw (canonical) error code corresponding to the enum value of

`google.rpc.Code` definitions within

https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto.

These values could be out of the range of canonical `absl::StatusCode`

enum values.

NOTE: This function should only be called when converting to an associated

wire format. Use `Status::code()` for error handling.

Status::message()

Returns the error message associated with this error code, if available.

Note that this message rarely describes the error code. It is not unusual

for the error message to be the empty string. As a result, prefer

`operator

<

<

` or `Status::ToString()` for debug logging.

Status::ToString()

Returns a string based on the `mode`. By default, it returns combination of

the error code name, the message and any associated payload messages. This

string is designed simply to be human readable and its exact format should

not be load bearing. Do not depend on the exact format of the result of

`ToString()` which is subject to change.

The printed code name and the message are generally substrings of the

result, and the payloads to be printed use the status payload printer

mechanism (which is internal).

Status::IgnoreError()

Ignores any errors. This method does nothing except potentially suppress

complaints from any tools that are checking that errors are not dropped on

the floor.

Status::GetPayload()

Gets the payload of a status given its unique `type_url` key, if present.

Status::SetPayload()

Sets the payload for a non-ok status using a `type_url` key, overwriting

any existing payload for that `type_url`.

NOTE: This function does nothing if the Status is ok.

Status::ErasePayload()

Erases the payload corresponding to the `type_url` key. Returns `true` if

the payload was present.

Status::ForEachPayload()

Iterates over the stored payloads and calls the

`visitor(type_key, payload)` callable for each one.

NOTE: The order of calls to `visitor()` is not specified and may change at

any time.

NOTE: Any mutation on the same 'absl::Status' object during visitation is

forbidden and could result in undefined behavior.