本文整理汇总了C++中Try::front方法的典型用法代码示例。如果您正苦于以下问题：C++ Try::front方法的具体用法？C++ Try::front怎么用？C++ Try::front使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Try的用法示例。
在下文中一共展示了Try::front方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: Error
// Reads `ProcessIO::Data` records from a string containing "Record-IO"
// data encoded in protobuf messages, and returns the stdout and stderr.
//
// NOTE: This function ignores any `ProcessIO::Control` records.
//
// TODO(gkleiman): This function is very similar to one in `api_tests.cpp`, we
// should refactor them into a common helper when fixing MESOS-7903.
static Try<tuple<string, string>> decodeProcessIOData(const string& data)
{
string stdoutReceived;
string stderrReceived;
::recordio::Decoder<v1::agent::ProcessIO> decoder(
lambda::bind(
deserialize<v1::agent::ProcessIO>,
ContentType::PROTOBUF,
lambda::_1));
Try<std::deque<Try<v1::agent::ProcessIO>>> records = decoder.decode(data);
if (records.isError()) {
return Error(records.error());
}
while (!records->empty()) {
Try<v1::agent::ProcessIO> record = records->front();
records->pop_front();
if (record.isError()) {
return Error(record.error());
}
if (record->data().type() == v1::agent::ProcessIO::Data::STDOUT) {
stdoutReceived += record->data().data();
} else if (record->data().type() == v1::agent::ProcessIO::Data::STDERR) {
stderrReceived += record->data().data();
}
}
return std::make_tuple(stdoutReceived, stderrReceived);
}示例2: Failure
Future<string> StoreProcess::_fetchImage(const Image::Appc& appc)
{
VLOG(1) << "Fetching image '" << appc.name() << "'";
Try<string> _tmpFetchDir = os::mkdtemp(
path::join(paths::getStagingDir(rootDir), "XXXXXX"));
if (_tmpFetchDir.isError()) {
return Failure(
"Failed to create temporary fetch directory for image '" +
appc.name() + "': " + _tmpFetchDir.error());
}
const string tmpFetchDir = _tmpFetchDir.get();
return fetcher->fetch(appc, Path(tmpFetchDir))
.then(defer(self(), [=]() -> Future<string> {
Try<list<string>> imageIds = os::ls(tmpFetchDir);
if (imageIds.isError()) {
return Failure(
"Failed to list images under '" + tmpFetchDir +
"': " + imageIds.error());
}
if (imageIds->size() != 1) {
return Failure(
"Unexpected number of images under '" + tmpFetchDir +
"': " + stringify(imageIds->size()));
}
const string& imageId = imageIds->front();
const string source = path::join(tmpFetchDir, imageId);
const string target = paths::getImagePath(rootDir, imageId);
if (os::exists(target)) {
LOG(WARNING) << "Image id '" << imageId
<< "' already exists in the store";
} else {
Try<Nothing> rename = os::rename(source, target);
if (rename.isError()) {
return Failure(
"Failed to rename directory '" + source +
"' to '" + target + "': " + rename.error());
}
}
Try<Nothing> addCache = cache->add(imageId);
if (addCache.isError()) {
return Failure(
"Failed to add image '" + appc.name() + "' with image id '" +
imageId + "' to the cache: " + addCache.error());
}
Try<Nothing> rmdir = os::rmdir(tmpFetchDir);
if (rmdir.isError()) {
return Failure(
"Failed to remove temporary fetch directory '" +
tmpFetchDir + "' for image '" + appc.name() + "': " +
rmdir.error());
}
return imageId;
}));
}