C / C++ / MFC

kaku_lala wrote:

Could someone help me write an implementation of strspn in ‘C’.

size_t strspn(const char *str, const char *chars)
begin
   result := 0
   for each c in str
   begin
      if  c is in chars then
         increment result
      else
         return result
      end if
   end
   
   return result
end

#include <iostream>

void *memset(char *s, char c, size_t n)
{
  size_t i;
  for (i = 0; i < n; i++, s++)
  {
    *s = c;
  }
  return s;
}

int main(int, char**)
{
   char p[100] = {0};
   memset(p, 'd', 10);
   std::cout << p << std::endl;
}

kaku_lala wrote:

Return s.

kaku_lala wrote:

I am getting an "access violation" when I execute the code in MS VC++ IDE.

void* memset1(void* s, char c, size_t n)
{
  char* p = (char*) s;
  for (size_t i = 0; i < n; i++)
  {
    p[i] = c;
  }
  return s;
}

template<class Elem, class Traits = std::char_traits<Elem> >
class basic_log_buffer : public std::basic_streambuf<Elem, Traits>
{
   // Override the necessary protected virtual functions
};

template<class Elem, class Traits = std::char_traits<Elem> >
class basic_log_stream : public std::basic_ostream<Elem, Traits>
{
public:
   LogStream() : basic_ostream(&my_buffer), my_buffer(whatever) {}
   // Override the necessary functions
private:
   basic_log_buffer<Elem, Traits> my_buffer;
};

namespace std
{
   ostream& operator<<(ostream& os, ostringstream& oss)
   {
      os << oss.str();
      // Clear the stringstream as we've used its content
      oss.str("");
      return os;
   }
}

std::ostringstream oss;
oss << "Hello";
std::cout << oss << std::endl;

• Some, or possibly all, local data items won't be accessible - hte compiler may have optimised away all need for them
• Some lines of code won't take a breakpoint. This is because they've been optimised away.
• The assembly language can be more difficult to trace to the source than when optimisations are turned off

BobInNJ wrote:

I am doing this by using the method CDC::TextOut in my OnPaint routine.