cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations math/log2l.c -o math/log2l -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv
math/log2l.c:5:35: error: ‘log2l’ undeclared here (not in a function); did you mean ‘logbl’?
    5 | long double (*foo)(long double) = log2l;
      |                                   ^~~~~
      |                                   logbl