On Wed, 14 Apr 2004 14:10:49 +0200, Rolf Magnus <ra******@t-online.de>
wrote:
Leor Zolman wrote:
On Tue, 13 Apr 2004 15:36:30 +0000 (UTC), Christopher Benson-Manica
<at***@nospam.cyberspace.org> wrote:
Leor Zolman <le**@bdsoft.com> spoke thus:
int y = 1944;
char buffer[10];
sprintf(buffer, "%d", y);
No problem in this case, but on my system, INT_MAX is 2147483647,
which is too big to fit in a 10-character buffer :)
Oops.
Can you even imagine how much money that kind of "oops" has already
destroyed? :-)
I only really started using std::string in earnest following a series of
pathname-related overrun bugs in the "Proxy" CL.EXE I distribute with
STLFilt, and I must admit I niether use nor miss fixed-sized C-string
buffers much any more. The ill-advised undersized buffer in my original
response here probably resulted from my brain seeing "1944", thinking
"years", and then upping the size a bit more for "safety".
If I did this sort of thing a lot today, which I actually don't, then I'd
be worried in general about buffer overruns and probably abstract out the
T-to-string conversion into a utility template library. Here's a first cut,
along with a test driver:
//
// tostring.h:
// T-to-std::string and T-to-char* conversion library
//
// Synopsis:
//
// std::string toString(const T &t);
// Converts t to std::string via operator<<
//
// char *toCString(char *dest, const T&t);
// Converts T to C-style string at dest, returns
// dest (calls toString above).
//
// Version 0.1
// Leor Zolman, 4/14/2004
//
#ifndef TOSTRING_H
#define TOSTRING_H
#include <sstream>
#include <string>
template<typename T>
std::string toString(const T& t)
{
std::ostringstream os;
os << t;
return os.str();
}
template<typename T>
inline char *toCString(char *dest, const T&t)
{
return strcpy(dest, toString(t).c_str());
}
/*
// This one we'd only ever want for performance reasons:
std::string toString(const std::string &t)
{
return t;
}
*/
// And this covers the last pathological case:
inline const char *toCString(const char *t)
{
return t;
}
#endif
//
// tostrtest.cpp: Test tostring.h library
//
#include "tostring.h"
int main()
{
using namespace std;
char buffer[1000]; // ;-)
int y = 1944;
strcpy(buffer, toString(y).c_str());
cout << "from int: " << buffer << endl;
cout << "from int: " << toCString(buffer, y) << endl;
double d = 1944.44;
strcpy(buffer, toString(d).c_str());
cout << "from double: " << buffer << endl;
cout << "from double: " << toCString(buffer, d) << endl;
string s = "1944 was a great year";
strcpy(buffer, toString(s).c_str());
cout << "from a string: " << buffer << endl;
cout << "from a string: " << toCString(buffer, s) << endl;
strcpy(buffer, toString("this is a dumb").c_str());
cout << "from a char *: " << buffer << endl;
cout << "from a char *: " <<
toCString(buffer, "another dumb one") << endl;
return 0;
}
-leor
--
Leor Zolman --- BD Software ---
www.bdsoft.com
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