OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Optimize filesystem::path::parent_path() 

Parsing a complete string is more efficient than appending each
component one-by-one.

	* src/c++17/fs_path.cc (path::parent_path()): Create whole path at
	once instead of building it iteratively.

From-SVN: r271754
This commit is contained in:
Jonathan Wakely 2019-05-29 23:00:45 +01:00 committed by Jonathan Wakely
parent e800d6dc2c
commit e5ccb10ad0
2 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
libstdc++-v3/ChangeLog
View File

@ -1,5 +1,8 @@
2019-05-29 Jonathan Wakely <jwakely@redhat.com>
* src/c++17/fs_path.cc (path::parent_path()): Create whole path at
once instead of building it iteratively.
* testsuite/util/testsuite_api.h: Remove names of unused parameters.
PR libstdc++/85494 use rdseed and rand_s in std::random_device

8
libstdc++-v3/src/c++17/fs_path.cc
View File

@ -1523,11 +1523,9 @@ path::parent_path() const
__ret = *this;
else if (_M_cmpts.size() >= 2)
{
for (auto __it = _M_cmpts.begin(), __end = std::prev(_M_cmpts.end());
__it != __end; ++__it)
{
__ret /= *__it;
}
const auto parent = std::prev(_M_cmpts.end(), 2);
const auto len = parent->_M_pos + parent->_M_pathname.length();
__ret.assign(_M_pathname.substr(0, len));
}
return __ret;
}