⭐ 欢迎来到虫虫下载站! | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站

📄 optional_value.cpp

📁 Boost provides free peer-reviewed portable C++ source libraries. We emphasize libraries that work
💻 CPP
字号:
//  (C) Copyright Gennadiy Rozental 2001-2008.//  Distributed under the Boost Software License, Version 1.0.//  (See accompanying file LICENSE_1_0.txt or copy at //  http://www.boost.org/LICENSE_1_0.txt)//  See http://www.boost.org/libs/test for the library home page.// Boost.Runtime.Param#include <boost/test/utils/runtime/cla/named_parameter.hpp>#include <boost/test/utils/runtime/cla/parser.hpp>namespace rt  = boost::runtime;namespace cla = boost::runtime::cla;// STL#include <iostream>#include <iterator>namespace boost {template<typename T>inline std::ostream&operator<<( std::ostream& ostr, boost::optional<T> const& v ){    if( v )        ostr << *v;    return ostr;}}int main() {    {        char* argv[] = { "basic", "-abcd", "-klmn", "10" };        int argc = sizeof(argv)/sizeof(char*);        try {            cla::parser P;            P << cla::named_parameter<int>( "abcd" ) - cla::optional_value              << cla::named_parameter<int>( "klmn" );            P.parse( argc, argv );            boost::optional<int> v = P.get<boost::optional<int> >( "abcd" );            std::cout << "abcd " << ( v ? "present" : "not present" ) << std::endl;            std::cout << "klmn = " << P.get<int>( "klmn" ) << std::endl;        }        catch( rt::logic_error const& ex ) {            std::cout << "Logic error: " << ex.msg() << std::endl;            return -1;        }    }    {        char* argv[] = { "basic", "-abcd", "25", "-klmn", "10" };        int argc = sizeof(argv)/sizeof(char*);        try {            cla::parser P;            P << cla::named_parameter<int>( "abcd" ) - cla::optional_value              << cla::named_parameter<int>( "klmn" );            P.parse( argc, argv );            boost::optional<int> v = P.get<boost::optional<int> >( "abcd" );            if( v )                std::cout << "*******\n""abcd = " << *v << std::endl;            std::cout << "klmn = " << P.get<int>( "klmn" ) << std::endl;        }        catch( rt::logic_error const& ex ) {            std::cout << "Logic error: " << ex.msg() << std::endl;            return -1;        }    }    {        char* argv[] = { "basic", "-abcd", "25", "-abcd", "-abcd", "10" };        int argc = sizeof(argv)/sizeof(char*);        try {            cla::parser P;            P << cla::named_parameter<int>( "abcd" ) - (cla::optional_value, cla::multiplicable);            P.parse( argc, argv );            typedef std::list<boost::optional<int> > value_type;            value_type v = P.get<value_type>( "abcd" );            std::cout << "*******\n""abcd = ";            std::copy( v.begin(), v.end(), std::ostream_iterator<boost::optional<int> >( std::cout, ", " ) );            std::cout << std::endl;        }        catch( rt::logic_error const& ex ) {            std::cout << "Logic error: " << ex.msg() << std::endl;            return -1;        }    }    return 0;}// EOF

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -