C++
clang HEAD 12.0.0 (https://github.com/llvm/llvm-project.git 9087209314caafed4b232d4a66287f2d16054ad3)
$ clang++ prog.cc -Wall -Wextra -I/opt/wandbox/boost-1.73.0/clang-head/include -std=c++2a prog.cc:11:6: warning: equality comparison result unused [-Wunused-comparison]
i == func(); // C4553
~~^~~~~~~~~
prog.cc:11:6: note: use '=' to turn this equality comparison into an assignment
i == func(); // C4553
^~
=
prog.cc:11:4: warning: variable 'i' is uninitialized when used here [-Wuninitialized]
i == func(); // C4553
^
prog.cc:10:9: note: initialize the variable 'i' to silence this warning
int i;
^
= 0
2 warnings generated.