本文整理汇总了C++中Ptree::pop_back方法的典型用法代码示例。如果您正苦于以下问题：C++ Ptree::pop_back方法的具体用法？C++ Ptree::pop_back怎么用？C++ Ptree::pop_back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Ptree的用法示例。
在下文中一共展示了Ptree::pop_back方法的1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: read_ini
void read_ini(std::basic_istream<
typename Ptree::key_type::value_type> &stream,
Ptree &pt)
{
typedef typename Ptree::key_type::value_type Ch;
typedef std::basic_string<Ch> Str;
const Ch semicolon = stream.widen(';');
const Ch hash = stream.widen('#');
const Ch lbracket = stream.widen('[');
const Ch rbracket = stream.widen(']');
Ptree local;
unsigned long line_no = 0;
Ptree *section = 0;
Str line;
// For all lines
while (stream.good())
{
// Get line from stream
++line_no;
std::getline(stream, line);
if (!stream.good() && !stream.eof())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"read error", "", line_no));
// If line is non-empty
line = property_tree::detail::trim(line, stream.getloc());
if (!line.empty())
{
// Comment, section or key?
if (line[0] == semicolon || line[0] == hash)
{
// Ignore comments
}
else if (line[0] == lbracket)
{
// If the previous section was empty, drop it again.
if (section && section->empty())
local.pop_back();
typename Str::size_type end = line.find(rbracket);
if (end == Str::npos)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"unmatched '['", "", line_no));
Str key = property_tree::detail::trim(
line.substr(1, end - 1), stream.getloc());
if (local.find(key) != local.not_found())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"duplicate section name", "", line_no));
section = &local.push_back(
std::make_pair(key, Ptree()))->second;
}
else
{
Ptree &container = section ? *section : local;
typename Str::size_type eqpos = line.find(Ch('='));
if (eqpos == Str::npos)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"'=' character not found in line", "", line_no));
if (eqpos == 0)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"key expected", "", line_no));
Str key = property_tree::detail::trim(
line.substr(0, eqpos), stream.getloc());
Str data = property_tree::detail::trim(
line.substr(eqpos + 1, Str::npos), stream.getloc());
if (container.find(key) != container.not_found())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"duplicate key name", "", line_no));
container.push_back(std::make_pair(key, Ptree(data)));
}
}
}
// If the last section was empty, drop it again.
if (section && section->empty())
local.pop_back();
// Swap local ptree with result ptree
pt.swap(local);
}