Find max consecutive sum in array

Find max consecutive sum in array
int foo(vector a)
{
int max=0;
int tmp_max=0;
for(int idx=0;idx < a.size();idx++)
{
tmp_max+=a[idx];
if(tmp_max<0)
tmp_max=0;
if(tmp_max>max)
max=tmp_max;
}
return max;
}