convert/example/stream.cpp

102 lines
2.6 KiB
C++

// Copyright (c) 2009-2016 Vladimir Batov.
// Use, modification and distribution are subject to the Boost Software License,
// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
#include <boost/convert.hpp>
#include <boost/convert/lexical_cast.hpp>
//[stream_headers1
#include <boost/convert.hpp>
#include <boost/convert/stream.hpp>
#include <boost/detail/lightweight_test.hpp>
using std::string;
using boost::convert;
struct boost::cnv::by_default : boost::cnv::cstream {};
//]
//[stream_headers2
namespace cnv = boost::cnv;
namespace arg = boost::cnv::parameter;
//]
#include "../test/test.hpp"
static
void
example1()
{
//[stream_example1
int i2 = convert<int>("123").value(); // Throws when fails.
int i3 = convert<int>("uhm").value_or(-1); // Returns -1 when fails.
string s2 = convert<string>(123).value();
BOOST_TEST(i2 == 123);
BOOST_TEST(i3 == -1);
BOOST_TEST(s2 == "123");
//]
}
static
void
example2()
{
//[stream_example2
boost::cnv::cstream ccnv;
boost::cnv::wstream wcnv;
int v01 = convert<int>(" FF", ccnv(std::hex)(std::skipws)).value_or(0);
int v02 = convert<int>(L" F", wcnv(std::hex)(std::skipws)).value_or(0);
int v03 = convert<int>(" FF", ccnv(std::dec)(std::skipws)).value_or(-5);
int v04 = convert<int>(L" F", wcnv(std::dec)(std::skipws)).value_or(-5);
BOOST_TEST(v01 == 255); // "FF"
BOOST_TEST(v02 == 15); // L"F"
BOOST_TEST(v03 == -5); // Failed to convert "FF" as decimal.
BOOST_TEST(v04 == -5); // Failed to convert L"F" as decimal.
//]
//[stream_example3
ccnv(std::showbase)(std::uppercase)(std::hex);
BOOST_TEST(convert<string>(255, ccnv, "bad") == "0XFF");
BOOST_TEST(convert<string>( 15, ccnv, "bad") == "0XF");
//]
//[stream_example4
ccnv(arg::base = cnv::base::dec)
(arg::uppercase = true)
(arg::notation = cnv::notation::scientific);
//]
//[stream_example5
ccnv(std::dec)(std::uppercase)(std::scientific);
//]
}
static
void
example6()
{
//[stream_example6
boost::cnv::cstream cnv1;
boost::cnv::lexical_cast cnv2;
change chg = change::up;
string s1 = convert<string>(chg, cnv1, "bad"); // Input type (change) deduced
string s2 = convert<string, change>(change::dn, cnv1, "bad"); // Input type (change) enforced
BOOST_TEST(convert<change>("up", cnv1, change::no) == change::up);
BOOST_TEST(convert<change>("up", cnv2, change::no) == change::up);
BOOST_TEST(s1 == "up");
BOOST_TEST(s2 == "dn");
//]
}
int
main(int, char const* [])
{
example1();
example2();
example6();
return boost::report_errors();
}