error: ISO C++17 does not allow 'register' storage class specifier
tianjiaoding opened this issue · comments
Hi Daniel,
It seems that my MacOS can not compile the project successfully, with complaints that seem to relate C++17 and compiler options. Maybe the project is not intended to be compiled on MacOS, but since the readme mentions C++17, I am just wondering if you happen to have ideas on what is going on here:
Scanning dependencies of target GraphCutRANSAC Scanning dependencies of target pygcransac [ 7%] Building CXX object CMakeFiles/GraphCutRANSAC.dir/src/pygcransac/include/GCoptimization.cpp.o In file included from /Users/richardding/Dropbox/graph-cut-ransac/src/pygcransac/include/GCoptimization.cpp:4: In file included from /Users/richardding/Dropbox/graph-cut-ransac/src/pygcransac/include/GCoptimization.h:109: /Users/richardding/Dropbox/graph-cut-ransac/src/pygcransac/include/energy.h:262:2: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister] register Value pi = (E000 + E011 + E101 + E110) - (E100 + E010 + E001 + E111); ^~~~~~~~~ /Users/richardding/Dropbox/graph-cut-ransac/src/pygcransac/include/energy.h:263:2: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister] register Value delta; ^~~~~~~~~ /Users/richardding/Dropbox/graph-cut-ransac/src/pygcransac/include/energy.h:264:2: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister] register Var u; ^~~~~~~~~
I am running cmake 3.15.5, with gcc configuration
gcc --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1 Apple LLVM version 10.0.1 (clang-1001.0.46.4) Target: x86_64-apple-darwin18.2.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Any insights would be appreciated!
I resolved this problem. My first attempt is to use C++14, but the use of C++17 feature std::clamp prevents me from doing so. Then I searched to see what is register. It seems from this page that this is similar to auto. And since the type has already been specified (e.g., type Value), it can be removed safely without semantically changing anything.
I am happy you solved it!
This was an issue earlier as well: #13
Aha, I forgot to check the issues that are closed. Thanks for your reply. Anyhow, I proposed a pull request #24 addressing this issue. Hope this will save time for others.