我需要递归遍历目录;我从SO上的另一个线程得到了一个相当不错的函数;为了我的目的，它只是一点点适应它，它在Mac上完美地工作，增强1.62和clang。
然而，我们正在使用SemaphoreCI（基于ubuntu 14.04 LTS并提升1.54），我无法在这些条件下进行编译。
#include <boost/algorithm/string/replace.hpp>
#include <boost/filesystem.hpp>
#include <boost/range.hpp>
void copyDirectoryRecursively(const fs::path& sourceDir, const fs::path& destinationDir)
{
if (!fs::exists(sourceDir) || !fs::is_directory(sourceDir))
{
throw std::runtime_error("Source directory " + sourceDir.string() + " does not exist or is not a directory");
}
if (!fs::create_directory(destinationDir) && !fs::exists(destinationDir))
{
throw std::runtime_error("Cannot create destination directory " + destinationDir.string());
}
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
{
const auto& path = dirEnt.path();
auto relativePathStr = path.string();
boost::algorithm::replace_first(relativePathStr, sourceDir.string(), "");
try {
if (!fs::is_directory(path)) { fs::copy_file(path, destinationDir / relativePathStr); }
else { fs::copy_directory(path, destinationDir / relativePathStr); }
}
catch (...) {
throw std::runtime_error("Cannot copy file " + path.string() + ", because it already exists in the destination folder.");
}
}
}
这是我得到的错误，
海湾合作委员会：/home/runner/performous/game/fs.cc: In function ‘void copyDirectoryRecursively(const boost::filesystem::path&, const boost::filesystem::path&)’:
/home/runner/performous/game/fs.cc:74:73: error: no matching function for call to ‘begin(boost::filesystem::recursive_directory_iterator&)’
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
^
/home/runner/performous/game/fs.cc:74:73: note: candidates are:
In file included from /usr/include/c++/4.8/string:51:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/boost/variant/variant.hpp:31,
from /home/runner/performous/game/configuration.hh:3,
from /home/runner/performous/game/fs.cc:2:
/usr/include/c++/4.8/bits/range_access.h:87:5: note: template<class _Tp, long unsigned int _Nm> _Tp* std::begin(_Tp (&)[_Nm])
^
/usr/include/c++/4.8/bits/range_access.h:87:5: note: template argument deduction/substitution failed:
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/bits/ios_base.h:41,
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
from /usr/include/c++/4.8/ios:42,
from /usr/include/boost/variant/detail/move.hpp:22,
from /usr/include/c++/4.8/iterator:64,
from /usr/include/boost/variant/detail/initializer.hpp:23,
from /usr/include/c++/4.8/iterator:64,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/boost/variant.hpp:17,
begin(_Tp (&__arr)[_Nm])
from /usr/include/boost/variant/detail/move.hpp:22,
from /usr/include/boost/variant/detail/initializer.hpp:23,
from /usr/include/boost/variant/variant.hpp:31,
/home/runner/performous/game/fs.cc:74:73: note: mismatched types ‘_Tp [_Nm]’ and ‘boost::filesystem::recursive_directory_iterator’
from /usr/include/boost/variant.hpp:17,
^
In file included from /usr/include/c++/4.8/string:51:0,
from /home/runner/performous/game/configuration.hh:3,
from /home/runner/performous/game/fs.cc:2:
from /usr/include/c++/4.8/bits/locale_classes.h:40,
begin(const _Container& __cont) -> decltype(__cont.begin())
/usr/include/c++/4.8/bits/range_access.h:58:5: note: template<class _Container> decltype (__cont.begin()) std::begin(const _Container&)
/usr/include/c++/4.8/bits/range_access.h: In substitution of ‘template<class _Container> decltype (__cont.begin()) std::begin(const _Container&) [with _Container = boost::filesystem::recursive_directory_iterator]’:
/usr/include/c++/4.8/bits/range_access.h:58:5: note: template argument deduction/substitution failed:
from /usr/include/c++/4.8/bits/ios_base.h:41,
/home/runner/performous/game/fs.cc:74:73: required from here
/usr/include/c++/4.8/bits/range_access.h:58:5: error: ‘const class boost::filesystem::recursive_directory_iterator’ has no member named ‘begin’
from /usr/include/c++/4.8/ios:42,
/usr/include/c++/4.8/bits/range_access.h:48:5: note: template<class _Container> decltype (__cont.begin()) std::begin(_Container&)
begin(_Container& __cont) -> decltype(__cont.begin())
^
/usr/include/c++/4.8/bits/range_access.h: In substitution of ‘template<class _Container> decltype (__cont.begin()) std::begin(_Container&) [with _Container = boost::filesystem::recursive_directory_iterator]’:
/usr/include/c++/4.8/bits/range_access.h:48:5: error: ‘class boost::filesystem::recursive_directory_iterator’ has no member named ‘begin’
/home/runner/performous/game/fs.cc:74:73: required from here
from /usr/include/boost/config/no_tr1/utility.hpp:21,
In file included from /usr/include/c++/4.8/utility:74:0,
from /usr/include/boost/config/select_stdlib_config.hpp:37,
from /usr/include/boost/config.hpp:40,
^
from /usr/include/boost/variant/detail/config.hpp:16,
from /usr/include/boost/variant/variant.hpp:23,
from /usr/include/boost/variant.hpp:17,
from /home/runner/performous/game/configuration.hh:3,
/usr/include/c++/4.8/initializer_list:89:5: note: template<class _Tp> constexpr const _Tp* std::begin(std::initializer_list<_Tp>)
from /home/runner/performous/game/fs.cc:2:
begin(initializer_list<_Tp> __ils) noexcept
^
/usr/include/c++/4.8/bits/range_access.h:48:5: note: template argument deduction/substitution failed:
/usr/include/c++/4.8/initializer_list:89:5: note: template argument deduction/substitution failed:
/home/runner/performous/game/fs.cc:74:73: note: ‘boost::filesystem::recursive_directory_iterator’ is not derived from ‘std::initializer_list<_Tp>’
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
/home/runner/performous/game/fs.cc:74:73: error: no matching function for call to ‘end(boost::filesystem::recursive_directory_iterator&)’
from /usr/include/c++/4.8/bits/locale_classes.h:40,
In file included from /usr/include/c++/4.8/string:51:0,
/home/runner/performous/game/fs.cc:74:73: note: candidates are:
from /usr/include/c++/4.8/iterator:64,
from /usr/include/c++/4.8/bits/ios_base.h:41,
^
from /usr/include/boost/variant/detail/move.hpp:22,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/ios:42,
from /usr/include/boost/variant/detail/initializer.hpp:23,
from /usr/include/boost/variant.hpp:17,
from /home/runner/performous/game/configuration.hh:3,
from /usr/include/boost/variant/variant.hpp:31,
/usr/include/c++/4.8/bits/range_access.h:97:5: note: template<class _Tp, long unsigned int _Nm> _Tp* std::end(_Tp (&)[_Nm])
from /home/runner/performous/game/fs.cc:2:
/usr/include/c++/4.8/bits/range_access.h:97:5: note: template argument deduction/substitution failed:
^
end(_Tp (&__arr)[_Nm])
/home/runner/performous/game/fs.cc:74:73: note: mismatched types ‘_Tp [_Nm]’ and ‘boost::filesystem::recursive_directory_iterator’
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
^
In file included from /usr/include/c++/4.8/string:51:0,
from /usr/include/c++/4.8/bits/locale_classes.h:40,
from /usr/include/c++/4.8/bits/ios_base.h:41,
from /usr/include/c++/4.8/ios:42,
from /usr/include/c++/4.8/ostream:38,
from /usr/include/c++/4.8/iterator:64,
from /usr/include/boost/variant/detail/move.hpp:22,
from /usr/include/boost/variant.hpp:17,
from /usr/include/boost/variant/variant.hpp:31,
from /usr/include/boost/variant/detail/initializer.hpp:23,
from /home/runner/performous/game/configuration.hh:3,
from /home/runner/performous/game/fs.cc:2:
^
end(const _Container& __cont) -> decltype(__cont.end())
/usr/include/c++/4.8/bits/range_access.h:78:5: note: template<class _Container> decltype (__cont.end()) std::end(const _Container&)
/usr/include/c++/4.8/bits/range_access.h: In substitution of ‘template<class _Container> decltype (__cont.end()) std::end(const _Container&) [with _Container = boost::filesystem::recursive_directory_iterator]’:
/usr/include/c++/4.8/bits/range_access.h:78:5: note: template argument deduction/substitution failed:
/home/runner/performous/game/fs.cc:74:73: required from here
/usr/include/c++/4.8/bits/range_access.h:78:5: error: ‘const class boost::filesystem::recursive_directory_iterator’ has no member named ‘end’
end(_Container& __cont) -> decltype(__cont.end())
/usr/include/c++/4.8/bits/range_access.h:68:5: note: template<class _Container> decltype (__cont.end()) std::end(_Container&)
/usr/include/c++/4.8/bits/range_access.h:68:5: note: template argument deduction/substitution failed:
^/usr/include/c++/4.8/bits/range_access.h: In substitution of ‘template<class _Container> decltype (__cont.end()) std::end(_Container&) [with _Container = boost::filesystem::recursive_directory_iterator]’:
/home/runner/performous/game/fs.cc:74:73: required from here
/usr/include/c++/4.8/bits/range_access.h:68:5: error: ‘class boost::filesystem::recursive_directory_iterator’ has no member named ‘end’
In file included from /usr/include/c++/4.8/utility:74:0,
from /usr/include/boost/config/no_tr1/utility.hpp:21,
from /usr/include/boost/config/select_stdlib_config.hpp:37,
from /usr/include/boost/config.hpp:40,
from /usr/include/boost/variant/detail/config.hpp:16,
from /usr/include/boost/variant/variant.hpp:23,
from /usr/include/boost/variant.hpp:17,
from /home/runner/performous/game/configuration.hh:3,
from /home/runner/performous/game/fs.cc:2:
/usr/include/c++/4.8/initializer_list:99:5: note: template<class _Tp> constexpr const _Tp* std::end(std::initializer_list<_Tp>)
end(initializer_list<_Tp> __ils) noexcept
^
/usr/include/c++/4.8/initializer_list:99:5: note: template argument deduction/substitution failed:
/home/runner/performous/game/fs.cc:74:73: note: ‘boost::filesystem::recursive_directory_iterator’ is not derived from ‘std::initializer_list<_Tp>’
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
^
make[2]: *** [game/CMakeFiles/performous.dir/fs.cc.o] Error 1
make[1]: *** [game/CMakeFiles/performous.dir/all] Error 2
make: *** [all] Error 2
Clang：
/home/runner/performous/game/fs.cc:74:29: error: invalid range expression of
type 'boost::filesystem::recursive_directory_iterator'; no viable 'begin'
function available
for (const auto& dirEnt : fs::recursive_directory_iterator{sourceDir})
^ ~~
1 error generated.
make[2]: *** [game/CMakeFiles/performous.dir/fs.cc.o] Error 1
make[1]: *** [game/CMakeFiles/performous.dir/all] Error 2
make: *** [all] Error 2
答案 0 :(得分：2)
当时，迭代器没有对范围概念进行建模。所以，只需制作自己的范围：
for (const auto& dirEnt : boost::make_iterator_range(fs::recursive_directory_iterator{sourceDir}, {})) {