converting _int64 to a string

I had a question when provid开发者_开发技巧ing an API

if I ask for them to give me a _int64 10 digit hexadecimal number but my function internally takes strings how do I effectively convert that...

as of right now I was just using string internally but for compatibility reasons i was using char* c style so that give any system 32 or 64 it wouldn't matter. Is that the accurate thing to do? or am i wrong?

is there a problem using char* vs _int64?

C++11 standardized the std::to_string function:

#include <string>

int main()
{
  int64_t value = 128;
  std::string asString = std::to_string(value);
  return 0;
}

#include <string>
#include <sstream>

int main()
{
  std::stringstream stream;
  __int64 value(1000000000);
  stream << value;    
  std::string strValue(stream.str());
  return 0;
}

The best option is to change the function to not use strings anymore so you can pass the original __int64 as-is. __int64 works the same in 32-bit and 64-bit systems.

If you have to convert to a string, there are several options. Steve showed you how to use a stringstream, which is the C++ way to do it. You can also use the C sprintf() or _i64toa() functions:

__int64 value = ...;
char buffer[20];
sprintf(buffer, "%Ld", value);

__int64 value = ...;
char buffer[20];
_i64toa(value, buffer, 10);