Is there a gcc flag to catch integer truncation?

Question

Is there a gcc flag to signal a warning/error when I try to put a double value into an int variable? I currently have -Wall -Wex

Answer 1

Yes, use the -Wfloat-conversion option:

-Wfloat-conversion

Warn for implicit conversions that reduce the precision of a real value. This includes conversions from real to integer, and from higher precision real to lower precision real values. This option is also enabled by -Wconversion.