__GNU_CXX::CONSTANT_UNARY_FUN(3CXX) - Linux man page online | Library functions
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Tue Mar 10 2020
__gnu_cxx::constant_unary_fun< _Result, __gnu_cxx::constant_unary_fun< _Result, _Argument >(3cxx)
libstdc++ __gnu_cxx::constant_unary_fun< _Result, _Argument >(3cxx)