Mega Code Archive
Use function defined in a namespace
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/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <cstdlib>
namespace MyLib {
double readAndProcessSum (std::istream&);
}
int main()
{
using namespace std;
double sum;
try {
sum = MyLib::readAndProcessSum(cin);
}
catch (const ios::failure& error) {
cerr << "I/O exception: " << error.what() << endl;
return EXIT_FAILURE;
}
catch (const exception& error) {
cerr << "standard exception: " << error.what() << endl;
return EXIT_FAILURE;
}
catch (...) {
cerr << "unknown exception" << endl;
return EXIT_FAILURE;
}
// print sum
cout << "sum: " << sum << endl;
}
#include <istream>
namespace MyLib {
double readAndProcessSum (std::istream& strm)
{
double value, sum;
/* while stream is OK
* - read value and add it to sum
*/
sum = 0;
while (strm >> value) {
sum += value;
}
if (!strm.eof()) {
throw std::ios::failure
("input error in readAndProcessSum()");
}
// return sum
return sum;
}
}
a
I/O exception: input error in readAndProcessSum()
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