paludis  Version 2.6.0
example_version_operator.cc

This example demonstrates how to use VersionOperator.

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/** \file
*
* Example \ref example_version_operator.cc "example_version_operator.cc" .
*
* \ingroup g_names
*/
/** \example example_version_operator.cc
*
* This example demonstrates how to use VersionOperator.
*/
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <set>
#include <list>
using namespace paludis;
using namespace examples;
using std::cout;
using std::endl;
using std::setw;
using std::left;
using std::boolalpha;
int main(int argc, char * argv[])
{
try
{
CommandLine::get_instance()->run(argc, argv,
"example_version_operator", "EXAMPLE_VERSION_OPERATOR_OPTIONS", "EXAMPLE_VERSION_OPERATOR_CMDLINE");
/* Make a set of versions. Use user_version_spec_options() for the
* options parameter for VersionSpec's constructor for handling any
* user-inputted data. */
std::set<VersionSpec> versions;
versions.insert(VersionSpec("1.0", user_version_spec_options()));
versions.insert(VersionSpec("1.1", user_version_spec_options()));
versions.insert(VersionSpec("1.2", user_version_spec_options()));
versions.insert(VersionSpec("1.2-r1", user_version_spec_options()));
versions.insert(VersionSpec("2.0", user_version_spec_options()));
/* And a list of operators */
std::list<VersionOperator> operators;
operators.push_back(VersionOperator("="));
operators.push_back(VersionOperator(">="));
operators.push_back(VersionOperator("~"));
operators.push_back(VersionOperator("<"));
operators.push_back(VersionOperator("~>"));
/* Display a header */
cout << " " << left << setw(8) << "LHS" << " | " << left << setw(8) << "RHS";
for (std::list<VersionOperator>::const_iterator o(operators.begin()), o_end(operators.end()) ;
o != o_end ; ++o)
cout << " | " << setw(8) << *o;
cout << endl << std::string(10, '-');
for (unsigned x(0) ; x <= operators.size() ; ++x)
cout << "+" << std::string(10, '-');
cout << endl;
/* For each pair of versions... */
for (std::set<VersionSpec>::const_iterator v1(versions.begin()), v1_end(versions.end()) ;
v1 != v1_end ; ++v1)
{
for (std::set<VersionSpec>::const_iterator v2(versions.begin()), v2_end(versions.end()) ;
v2 != v2_end ; ++v2)
{
cout << " " << left << setw(8) << *v1 << " | " << left << setw(8) << *v2;
/* Apply all of our operators, and show the results */
for (std::list<VersionOperator>::const_iterator o(operators.begin()), o_end(operators.end()) ;
o != o_end ; ++o)
{
/* VersionOperator::as_version_spec_comparator returns a
* binary boolean functor. */
cout << " | " << left << setw(8) << boolalpha << (o->as_version_spec_comparator()(*v1, *v2));
}
cout << endl;
}
}
}
catch (const Exception & e)
{
/* Paludis exceptions can provide a handy human-readable backtrace and
* an explanation message. Where possible, these should be displayed. */
cout << endl;
cout << "Unhandled exception:" << endl
<< " * " << e.backtrace("\n * ")
<< e.message() << " (" << e.what() << ")" << endl;
return EXIT_FAILURE;
}
catch (const std::exception & e)
{
cout << endl;
cout << "Unhandled exception:" << endl
<< " * " << e.what() << endl;
return EXIT_FAILURE;
}
catch (...)
{
cout << endl;
cout << "Unhandled exception:" << endl
<< " * Unknown exception type. Ouch..." << endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}