报错如下
duplicate symbol __ZN1A1aE in:
/Users/lanou3g/Library/Developer/Xcode/DerivedData/template-gapwonevjfxbmyeyoxqyfbrpztve/Build/Intermediates/template.build/Debug/template.build/Objects-normal/x86_64/A.o
/Users/lanou3g/Library/Developer/Xcode/DerivedData/template-gapwonevjfxbmyeyoxqyfbrpztve/Build/Intermediates/template.build/Debug/template.build/Objects-normal/x86_64/A1.o
duplicate symbol __ZN1A1aE in:
/Users/lanou3g/Library/Developer/Xcode/DerivedData/template-gapwonevjfxbmyeyoxqyfbrpztve/Build/Intermediates/template.build/Debug/template.build/Objects-normal/x86_64/A.o
/Users/lanou3g/Library/Developer/Xcode/DerivedData/template-gapwonevjfxbmyeyoxqyfbrpztve/Build/Intermediates/template.build/Debug/template.build/Objects-normal/x86_64/main.o
ld: 2 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)