// This is based on the example code found here: https:// svn.boost.org/trac/boost/ticket/1976
// but changed to not return a trailing ".." when paths only differ in their file name.
// The function still seems to be missing in boost as of 1.54.0.
FS_NAMESPACE::path naiveUncomplete(FS_NAMESPACE::path const path, FS_NAMESPACE::path const base)
{
if (path.has_root_path())
{
if (path.root_path() != base.root_path())
{
return path;
}
else
{
return naiveUncomplete(path.relative_path(), base.relative_path());
}
}
else
{
if (base.has_root_path())
{
return path;
}
else
{
auto path_it = path.begin();
auto base_it = base.begin();
while (path_it != path.end() && base_it != base.end())
{
if (*path_it != *base_it) break;
++path_it; ++base_it;
}
FS_NAMESPACE::path result;
// check if we're at the filename of the base path already
if (*base_it != base.filename())
{
// add trailing ".." from path to base, but only if we're not already at the filename of the base path
for (; base_it != base.end() && *base_it != base.filename(); ++base_it)
{
result /= "..";
}
}
for (; path_it != path.end(); ++path_it)
{
result /= *path_it;
}
return result;
}
}
return path;
}
