Issue
I'd like to know what switch you pass to the gcc compiler to turn off unused variable warnings? I'm getting errors out of boost on windows and I do not want to touch the boost code:
C:\boost_1_52_0/boost/system/error_code.hpp: At global scope:
C:\boost_1_52_0/boost/system/error_code.hpp:214:36: error: 'boost::system::posix_category' defined but not used [-Werror=unused-variable]
C:\boost_1_52_0/boost/system/error_code.hpp:215:36: error: 'boost::system::errno_ecat' defined but not used [-Werror=unused-variable]
C:\boost_1_52_0/boost/system/error_code.hpp:216:36: error: 'boost::system::native_ecat' defined but not used [-Werror=unused-variable]
I tried using both -Wunused-value and -Wno-unused-value but neither suppressed the messages above.
What is the right command, here is my compile line:
g++ -g -fno-inline -Wall -Werror -Wextra -Wfloat-equal -Wshadow
-Wpointer-arith -Wcast-qual -Wcast-align -Wwrite-strings -Wno-conversion
-Wdisabled-optimization -Wredundant-decls -Wunused-value -Wno-deprecated
-IC:\\boost_1_52_0 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
-c -o op.o op.cpp
Perhaps the -Wall overrides my goal?
Solution
The -Wno-unused-variable switch usually does the trick. However, that is a very useful warning indeed if you care about these things in your project. It becomes annoying when GCC starts to warn you about things not in your code though.
I would recommend you keeping the warning on, but use -isystem instead of -I for include directories of third-party projects. That flag tells GCC not to warn you about the stuff you have no control over.
For example, instead of -IC:\\boost_1_52_0, say -isystem C:\\boost_1_52_0.
Hope it helps. Good Luck!
Answered By - user405725