header - why my xcode can't find bits/stdc++.h file when there is one - OGeek|极客中国-技术改变生活,极客改变未来

From this pic: As you can see here,it shows that i have a foder with stdc++.h in i.But Xcode says it can't find the file. I've tried to make a new bits foder in /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include, but still i won't work. Can anybody help me with this problem? Thanks a lot!