foo.cc: In function 'int main()':
foo.cc:9:8: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
  -10^10<a<b<10^10;
      ~~^~
foo.cc:9:12: warning: comparison of constant '10' with boolean expression is always true [-Wbool-compare]
  -10^10<a<b<10^10;
      ~~~~~~^~~
foo.cc:9:10: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
  -10^10<a<b<10^10;
      ~~~~^~
foo.cc:9:12: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
  -10^10<a<b<10^10;
      ~~~~~~^~~
foo.cc:9:15: warning: statement has no effect [-Wunused-value]
  -10^10<a<b<10^10;
  ~~~~~~~~~~~~~^~~

[Hydro](https://hydro.ac)提供评测服务