gcc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations math/M_SQRT1_3.c -o math/M_SQRT1_3 -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lxnet -lsocket -latomic
math/M_SQRT1_3.c:8:21: error: 'M_SQRT1_3' undeclared here (not in a function); did you mean 'M_SQRT1_2'?
    8 | double  const foo = M_SQRT1_3;
      |                     ^~~~~~~~~
      |                     M_SQRT1_2