Using custom std::set comparator
- by Omry
I am trying to change the default order of the items in a set of integers to be lexicographic instead of numeric, and I can't get the following to compile with g++:
file.cpp:
bool lex_compare(const int64_t &a, const int64_t &b)
{
stringstream s1,s2;
s1 << a;
s2 << b;
return s1.str() < s2.str();
}
void foo()
{
set<int64_t, lex_compare> > s;
s.insert(1);
...
}
I get the following error:
error: type/value mismatch at argument 2 in template parameter list for ‘template<class _Key, class _Compare, class _Alloc> class std::set’
error: expected a type, got ‘lex_compare’
what am I doing wrong?
