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copied!<p>For pointers in general you could do this:</p> <pre><code> #include <ctime> #include <vector> #include <cstdlib> #include <algorithm> #include <functional> #include <type_traits> namespace util { struct sort_pointers { bool operator() ( int *a, int *b ) { return *a < *b; } }; template <typename T, bool is_pointer = !std::tr1::is_pointer<T>::value> struct sort_helper { typedef std::less<T> wont_compare_pointers; }; template <typename T> struct sort_helper<T,false> { }; template <typename Iterator> void sort( Iterator start, Iterator end ) { std::sort( start, end, sort_helper < typename Iterator::value_type >::wont_compare_pointers() ); } template <typename Iterator, class Func> void sort( Iterator start, Iterator end, Func f ) { std::sort( start, end, f ); } } int main() { std::vector<int> v1; std::vector<int*> v2; srand(time(0)); for( int i = 0; i < 10; ++i ) { v1.push_back(rand()); } util::sort( v1.begin(), v1.end() ); for( int i = 0; i < 10; ++i ) { v2.push_back(&v1[i]); } /* util::sort( v2.begin(), v2.end() ); */ //fails. util::sort( v2.begin(), v2.end(), util::sort_pointers() ); return 0; } </code></pre> <p><code>std::tr1::is_pointer</code> was just what it was called in Visual Studio 2008, but I think Boost has one too, and newer compiles might provide it as <code>std::is_pointer</code>. I'm sure someone would be able to write a prettier solution, but this appears to work.</p> <p>But I must say, I agree with cogwheel, there is no reason for this, the programmer should be able to see if this is going to be a problem and act accordingly.</p> <p>Addition:</p> <p>You can generalize it a bit more I think, to automatically select a functor that will dereference the pointers and compare the values:</p> <pre><code>namespace util { template <typename T> struct sort_pointers { bool operator() ( T a, T b ) { return *a < *b; } }; template <typename T, bool is_pointer = !std::tr1::is_pointer<T>::value> struct sort_helper { typedef std::less<T> compare; }; template <typename T> struct sort_helper<T,false> { typedef sort_pointers<T> compare; }; template <typename Iterator> void sort( Iterator start, Iterator end ) { std::sort( start, end, sort_helper < typename Iterator::value_type >::compare() ); } } </code></pre> <p>That way you don't have to think about if you're providing it with pointers to compare or not, it will automatically be sorted out.</p>

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