Home > C++ > FAQ C++ > FAQ C++ - gcc/g++ > gcc /g++ Why some variables are not detected as not used during (...)
gcc /g++ Why some variables are not detected as not used during compilation?
Sunday 12 June 2011, by
Keywords: C , C++ , compilation , g++ , gcc .
In the following example, variable x is not detected as not used
#include <vector>
int main()
{
std::vector< double > x;
int k,l;
}g++ -Wall test.cpp
test.cpp: In function 'int main()':
test.cpp:6:6: warning: unused variable 'k'
test.cpp:6:8: warning: unused variable 'l'Actually, warnings are only declared for built in types (bool, int, float, double, etc ...). Compiler can’t determine if removing declaration of x would change the behaviour of semantics program.
