template< typename T > struct FixedVector
{
    T * ptr;
    size_t count;

    typedef T value_type;

    FixedVector():ptr(0),count(0) {}
    ~FixedVector()
    {
        DeleteArr(ptr); // Error message appears here
        count=0;
    }
// ...
}

template< typename T > inline void DeleteArr( T *& ptr )
{
    delete[] ptr;
    ptr = NULL;
}

error: call to function 'DeleteArr' that is neither visible in the template definition nor found by argument-dependent lookup

'DeleteArr' should be declared prior to the call site or in an associated namespace of one of its arguments.

template< typename T > inline void DeleteArr( T *& ptr );

template< typename T > inline void DeleteArr( T *& ptr )
    {
        delete[] ptr;
        ptr = NULL;
    }

template< typename T > struct FixedVector
{
    T * ptr;
    size_t count;

    typedef T value_type;

    FixedVector():ptr(0),count(0) {}
    ~FixedVector()
    {
        DeleteArr(ptr); // Error message appears here
        count=0;
    }
// ...
}