better comments in PathUtilities.cpp

This commit is contained in:
walker0643 2018-04-01 14:47:34 -04:00
parent 1734e6d7f6
commit 42a8f69050
1 changed files with 19 additions and 6 deletions

View File

@ -15,6 +15,19 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
These functions cover the vast majority of cases for different paths across
windows and unixes. They are not, however, fullproof and probably don't cover
fringe cases very well. The library below might be used as an alternative if
these implementations prove to be insufficient. As the library's readme states
it is simply a temporary band-aid until std::filesystem is integrated (C++17
has it in std::experimental) and this class should also be treated as such.
https://github.com/wjakob/filesystem/
*/
#include "PathUtilities.h"
// keep the default platform delimiter as the first in the list
@ -41,22 +54,22 @@ std::string PathUtilities::concat(const std::string& left, const std::string& ri
++leftEnd;
auto rightStart = right.find_first_not_of(Delimiters, 0);
if (rightStart == std::string::npos) {
// l/r empty
// both left/right are empty
if (left.size() == 0 && right.size() == 0)
return "";
// r useless, l okay
// right is full of delims, left is okay
if (leftEnd > 0)
return left.substr(0, leftEnd);
// both useless but one has a delim
// both left/right useless but at least one has delims
return std::string(1, DefaultDelimiter);
}
if (leftEnd == 0) {
// r okay and not prefixed with delims, l empty
// right is okay and not prefixed with delims, left is empty
if (left.size() == 0 && rightStart == 0)
return right.substr(rightStart);
// r okay and prefixed with delims OR l full of delims
// (right is okay and prefixed with delims) OR left is full of delims
return DefaultDelimiter + right.substr(rightStart);
}
// normal concatenation
// concatenation using both left and right
return left.substr(0, leftEnd) + DefaultDelimiter + right.substr(rightStart);
}